Portable version degrading


Roger Stewart
 

I've noticed over the past couple years that my portable install of nvda will sometimes degrade or get a bit corrupted over time all by itself while the installed version is always stable as a rock. Does anyone know why this is and is there any way to prevent this from happening? I use the portable copy to test a couple add ons and if the portable version corrupts, it can make it appear that the add on is defective or has a bug while it really doesn't. Deleting the portable copy and making a new one will clear it up. I also notice a few functions of nvda either don't work at all or nvda gets very sluggish in responsiveness and this all gets back to normal after a complete flush and remake of the portable version. As I say, this never has happened at all with my installed copy on the same computer.


Roger


Gene
 

I don't know.  I would think the easiest way to deal with the situation would be not to make a new portable version, but to make a copy of the existing portable version when it is working properly and then delete and copy the portable version to where it was before.
 
Gene

----- Original Message -----
Sent: Thursday, January 18, 2018 2:10 PM
Subject: [nvda] Portable version degrading

I've noticed over the past couple years that my portable install of nvda
will sometimes degrade or get a bit corrupted over time all by itself
while the installed version is always stable as a rock.  Does anyone
know why this is and is there any way to prevent this from happening?  I
use the portable copy to test a couple add ons and if the portable
version corrupts, it can make it appear that the add on is defective or
has a bug while it really doesn't.  Deleting the portable copy and
making a new one will clear it up.  I also notice a few functions of
nvda either don't work at all or nvda gets very sluggish in
responsiveness and this all gets back to normal after a complete flush
and remake of the portable version.  As I say, this never has happened
at all with my installed copy on the same computer.


Roger





Brian's Mail list account <bglists@...>
 

Yes I do this as well. However it could be of cores that the degradation is due to some outside factor which is not obvious, like a once only scan from some kind of malware detector doing something its not supposed to.
Also if the person has quite a slow old type hard drive fragmentation can sometimes do things like this.
Brian

bglists@blueyonder.co.uk
Sent via blueyonder.
Please address personal email to:-
briang1@blueyonder.co.uk, putting 'Brian Gaff'
in the display name field.

----- Original Message -----
From: "Gene" <gsasner@ripco.com>
To: <nvda@nvda.groups.io>
Sent: Thursday, January 18, 2018 8:17 PM
Subject: Re: [nvda] Portable version degrading


I don't know. I would think the easiest way to deal with the situation would be not to make a new portable version, but to make a copy of the existing portable version when it is working properly and then delete and copy the portable version to where it was before.

Gene
----- Original Message -----

From: Roger Stewart
Sent: Thursday, January 18, 2018 2:10 PM
To: nvda@nvda.groups.io
Subject: [nvda] Portable version degrading


I've noticed over the past couple years that my portable install of nvda
will sometimes degrade or get a bit corrupted over time all by itself
while the installed version is always stable as a rock. Does anyone
know why this is and is there any way to prevent this from happening? I
use the portable copy to test a couple add ons and if the portable
version corrupts, it can make it appear that the add on is defective or
has a bug while it really doesn't. Deleting the portable copy and
making a new one will clear it up. I also notice a few functions of
nvda either don't work at all or nvda gets very sluggish in
responsiveness and this all gets back to normal after a complete flush
and remake of the portable version. As I say, this never has happened
at all with my installed copy on the same computer.


Roger


tonea.ctr.morrow@...
 

A few years back, I had a job for three years where people brought me their files on USB thumb drives. These things are horrible in terms of long-life. The really do have to be unmounted prior to removing from the computer or they get corrupted. They physically fall apart easily. And, the hardware inside seems to be more vulnerable to static electricity data loss than other portable drives, certainly more vulnerable than most computers.

 

I would think that would be the problem.

 

Tonea

 

-----Original Message-----

I've noticed over the past couple years that my portable install of nvda will sometimes degrade or get a bit corrupted over time all by itself while the installed version is always stable as a rock.  Does anyone know why this is and is there any way to prevent this from happening?  I use the portable copy to test a couple add ons and if the portable version corrupts, it can make it appear that the add on is defective or has a bug while it really doesn't.  Deleting the portable copy and making a new one will clear it up.  I also notice a few functions of nvda either don't work at all or nvda gets very sluggish in responsiveness and this all gets back to normal after a complete flush and remake of the portable version.  As I say, this never has happened at all with my installed copy on the same computer.

 

 

Roger

 


Antony Stone
 

USB drives do need to be unmounted before removing them, otherwise there is
the risk of file system corruption. Precisely the same is true for external
hard drives, floppy disks, or any other writeable medium you can temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're considerably
more robust than floppy disks, which is basically what they replaced. You can
also drop them on the floor with a good deal more confidence of them working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them have
plastic caps to put over the contacts or a slider to retract the contacts into
the body.

My experience is that if they're treated reasonably they work very well. If
they're mistreated they'll give as many problems as any other mistreated
storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from the
computer or they get corrupted. They physically fall apart easily. And,
the hardware inside seems to be more vulnerable to static electricity data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of nvda
will sometimes degrade or get a bit corrupted over time all by itself
while the installed version is always stable as a rock. Does anyone know
why this is and is there any way to prevent this from happening? I use
the portable copy to test a couple add ons and if the portable version
corrupts, it can make it appear that the add on is defective or has a bug
while it really doesn't. Deleting the portable copy and making a new one
will clear it up. I also notice a few functions of nvda either don't work
at all or nvda gets very sluggish in responsiveness and this all gets back
to normal after a complete flush and remake of the portable version. As I
say, this never has happened at all with my installed copy on the same
computer.





Roger
--
#define SIX 1+5
#define NINE 8+1

int main() {
printf("%d\n", SIX * NINE);
}
- thanks to ECB for bringing this to my attention

Please reply to the list;
please *don't* CC me.


Rob Hudson
 

Antony Stone <antony.stone@nvda.open.source.it> wrote:
I've never seen a USB thumb drive fall apart, and I think they're considerably
more robust than floppy disks, which is basically what they replaced. You can
also drop them on the floor with a good deal more confidence of them working
afterwards than if you drop an external hard disk.
I put my portable NVDA installs on S D cards and use a ten dollar USB card reader. The only way to hurt a card like that is to drop it in water, I guess. And most computers nowadays come with card readers built in to them.
If you're willing to pay a little more, you can buy USB flash drives in protective, rubberized or metal housings. These are a great deal sturdier than the cheapies you can get for a few bucks. Not only do those fall apart easily, but they will go corrupt faster. Even if you unmount them using the
"Safey Remove Hardware"
item on windows or the
"umount"
option in Linux. Solid state memory only has a limited number of reads/writes.
The least corruptible data medium I've heard of is vinyl records. I've heard you can actually listen to a vinyl record by spinning it and using a pine needle. They have buried some of our worlds most important speeches and such in the desert on vinyl. I'm not sure what it is about that medium specifically that makes it better suited for long term storage, though.


tonea.ctr.morrow@...
 

LOL!

 

I agree that S.D. cards are a better choice.

 

As for vinyl, the recording is so big that you can both see and feel it on the media. You can’t do that with any traditional computer format—I think that is what give it such stability. Small distortions to the recording don’t impede replay.

 

With regard to burying vinyl recordings in the desert: grains of sand would scratch out the recordings, so I assume you meant they are protectively wrapped and then buried. I still think that might not be such a good way to store vinyl. I remember in the 1970’s watching my mom heat a record in the oven and then lay it over a cup to create a vinyl bowl. Unless buried deep enough to not be subject to the heat, the record would be destroyed over time from heat and cold cycle, in my opinion. If buried deep enough to be consistent in temperature, then it becomes accessible to water damage. If you have a link to information on such burials, that would be an interesting read.

 

All in all though, I agree and think Vinyl has proved itself better at surviving than any computer format.  (grinning)

 

Tonea

 

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Rob Hudson
Sent: Friday, January 19, 2018 8:45 AM

I put my portable NVDA installs on S  D cards and use a ten dollar USB card reader. The only way to hurt a card like that is to drop it in water, I guess. And most computers nowadays come with card readers built in to them.

If you're willing to pay a little more, you can buy USB flash drives in protective, rubberized or metal housings. These are a great deal sturdier than the cheapies you can get for a few bucks. Not only do those fall apart easily, but they will go corrupt faster. Even if you unmount them using the "Safey Remove Hardware"

item on windows or the

"umount"

option in Linux. Solid state memory only has a limited number of reads/writes.

The least corruptible data medium I've heard of is vinyl records. I've heard you can actually listen to a vinyl record by spinning it and using a pine needle. They have buried some of our worlds most important speeches and such in the desert on vinyl. I'm not sure what it is about that medium specifically that makes it better suited for long term storage, though.


Rob Hudson
 

tonea.ctr.morrow@faa.gov wrote:
Unless buried deep enough to not be subject to the heat, the record would be destroyed over time from heat and cold cycle, in my opinion. If buried deep enough to be consistent in temperature, then it becomes accessible to water damage. If you have a link to information on such burials, that would be an interesting read.

Sorry, I don't. It was just something I heard on, I think, the Kommando radio show, about 20 years ago. It stuck in my mind, however, and I still remember the reference.
Another interesting tidbit I heard was archeologists trying to get voice fragments off pottery shards.
http://www.ohgizmo.com/2006/02/20/5000-year-old-recordings-caught-on-pottery/
I'm very fascinated by stuff like this. However, we're now venturing off grounds for this list, so I'll shut up, now.


Roger Stewart
 

The problem with this discussion is my portable version is on an internal hard drive. So why is this degrading?

Nothing else on this drive has any trouble and I've checked, and there's no file system errors nor any fragmenting.


Roger

On 1/19/2018 8:28 AM, Antony Stone wrote:
USB drives do need to be unmounted before removing them, otherwise there is
the risk of file system corruption. Precisely the same is true for external
hard drives, floppy disks, or any other writeable medium you can temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're considerably
more robust than floppy disks, which is basically what they replaced. You can
also drop them on the floor with a good deal more confidence of them working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them have
plastic caps to put over the contacts or a slider to retract the contacts into
the body.

My experience is that if they're treated reasonably they work very well. If
they're mistreated they'll give as many problems as any other mistreated
storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from the
computer or they get corrupted. They physically fall apart easily. And,
the hardware inside seems to be more vulnerable to static electricity data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of nvda
will sometimes degrade or get a bit corrupted over time all by itself
while the installed version is always stable as a rock. Does anyone know
why this is and is there any way to prevent this from happening? I use
the portable copy to test a couple add ons and if the portable version
corrupts, it can make it appear that the add on is defective or has a bug
while it really doesn't. Deleting the portable copy and making a new one
will clear it up. I also notice a few functions of nvda either don't work
at all or nvda gets very sluggish in responsiveness and this all gets back
to normal after a complete flush and remake of the portable version. As I
say, this never has happened at all with my installed copy on the same
computer.





Roger


Gene
 

Thumb drives aren't reliable enough to use as permanent backup but I've kept files on them for long periods of time with no problems.  I've had the same files elsewhere as well but floppy drives are reasonably reliable.
 
Gene

----- Original Message -----
Sent: Friday, January 19, 2018 8:28 AM
Subject: Re: [nvda] Portable version degrading

USB drives do need to be unmounted before removing them, otherwise there is
the risk of file system corruption.  Precisely the same is true for external
hard drives, floppy disks, or any other writeable medium you can temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're considerably
more robust than floppy disks, which is basically what they replaced.  You can
also drop them on the floor with a good deal more confidence of them working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them have
plastic caps to put over the contacts or a slider to retract the contacts into
the body.

My experience is that if they're treated reasonably they work very well.  If
they're mistreated they'll give as many problems as any other mistreated
storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@... wrote:

> A few years back, I had a job for three years where people brought me their
> files on USB thumb drives. These things are horrible in terms of
> long-life. The really do have to be unmounted prior to removing from the
> computer or they get corrupted. They physically fall apart easily. And,
> the hardware inside seems to be more vulnerable to static electricity data
> loss than other portable drives, certainly more vulnerable than most
> computers.
>
>
>
> I would think that would be the problem.
>
>
>
> Tonea
>
>
>
> -----Original Message-----
>
> I've noticed over the past couple years that my portable install of nvda
> will sometimes degrade or get a bit corrupted over time all by itself
> while the installed version is always stable as a rock.  Does anyone know
> why this is and is there any way to prevent this from happening?  I use
> the portable copy to test a couple add ons and if the portable version
> corrupts, it can make it appear that the add on is defective or has a bug
> while it really doesn't.  Deleting the portable copy and making a new one
> will clear it up.  I also notice a few functions of nvda either don't work
> at all or nvda gets very sluggish in responsiveness and this all gets back
> to normal after a complete flush and remake of the portable version.  As I
> say, this never has happened at all with my installed copy on the same
> computer.
>
>
>
>
>
> Roger

--
#define SIX 1+5
#define NINE 8+1

int main() {
    printf("%d\n", SIX * NINE);
}
- thanks to ECB for bringing this to my attention

                                                   Please reply to the list;
                                                         please *don't* CC me.



Gene
 

Sometimes things happen and you never know why.  Unless your hard drive is developing bad sectors, I doubt people will have possible explanations. 
 
Gene

----- Original Message -----
Sent: Friday, January 19, 2018 9:58 AM
Subject: Re: [nvda] Portable version degrading

The problem with this discussion is my portable version is on an
internal hard drive.  So why is this degrading?

Nothing else on this drive has any trouble and I've checked, and there's
no file system errors nor any fragmenting.


Roger












On 1/19/2018 8:28 AM, Antony Stone wrote:
> USB drives do need to be unmounted before removing them, otherwise there is
> the risk of file system corruption.  Precisely the same is true for external
> hard drives, floppy disks, or any other writeable medium you can temporarily
> attach to a computer.
>
> I've never seen a USB thumb drive fall apart, and I think they're considerably
> more robust than floppy disks, which is basically what they replaced.  You can
> also drop them on the floor with a good deal more confidence of them working
> afterwards than if you drop an external hard disk.
>
> Yes, they're vulnerable to static electricity; that's why most of them have
> plastic caps to put over the contacts or a slider to retract the contacts into
> the body.
>
> My experience is that if they're treated reasonably they work very well.  If
> they're mistreated they'll give as many problems as any other mistreated
> storage medium.
>
>
> Antony.
>
> On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@... wrote:
>
>> A few years back, I had a job for three years where people brought me their
>> files on USB thumb drives. These things are horrible in terms of
>> long-life. The really do have to be unmounted prior to removing from the
>> computer or they get corrupted. They physically fall apart easily. And,
>> the hardware inside seems to be more vulnerable to static electricity data
>> loss than other portable drives, certainly more vulnerable than most
>> computers.
>>
>>
>>
>> I would think that would be the problem.
>>
>>
>>
>> Tonea
>>
>>
>>
>> -----Original Message-----
>>
>> I've noticed over the past couple years that my portable install of nvda
>> will sometimes degrade or get a bit corrupted over time all by itself
>> while the installed version is always stable as a rock.  Does anyone know
>> why this is and is there any way to prevent this from happening?  I use
>> the portable copy to test a couple add ons and if the portable version
>> corrupts, it can make it appear that the add on is defective or has a bug
>> while it really doesn't.  Deleting the portable copy and making a new one
>> will clear it up.  I also notice a few functions of nvda either don't work
>> at all or nvda gets very sluggish in responsiveness and this all gets back
>> to normal after a complete flush and remake of the portable version.  As I
>> say, this never has happened at all with my installed copy on the same
>> computer.
>>
>>
>>
>>
>>
>> Roger





 

Hi,
It'll depend on what type of drive it is. If it's a traditional hard drive,
it'll degrade as data moves around, creating the need for defragmentation.
This is especially the case when data is repeatedly written and the file
system is asked to find new locations to hold the constantly changing data.
In case of solid-state drives, it'll degrade if the same region is written
repeatedly, as flash memory has limited endurance when it comes to data
reads and writes.
In case of Roger's issue: a possible contributing factor is constant add-on
updates. He uses an add-on that is updated on a regular basis, putting
strain on part of the drive where the add-on bits are stored. Thus, some
drive sectors are repeatedly bombarded with new information, and one way
operating systems will do in this case is move the new data somewhere else
on the drive, potentially fragmenting bits of files (I'll explain in a
moment). Thus one solution is to not test all add-on updates, but that's a
bit risky as Roger is one of the key testers for this add-on I'm talking
about.
Regarding fragmentation and what not: the following is a bit geeky but I
believe you should know about how some parts of a file system (an in
extension, operating systems) works, because I believe it'll help folks
better understand what might be going on:
Storage devices encountered in the wild are typically organized into many
parts, typically into blocks of fixed-length units called "sectors". A
sector is smallest unit of information that the storage device can present
to the outside world, as in how much data can be held on a storage device.
For example, when you store a small document on a hard disk drive (HDD) and
when you wish to open it in Notepad, Windows will ask a module that's in
charge of organizing and interpreting data on a drive (called a file system)
to locate the sector where the document (or magnets or flash cells that
constitute the document data) is stored and bring it out to you. To you, all
you see is the path to the document, but the file system will ask the drive
controller (a small computer inside hard disks and other storage devices) to
fetch data in a particular sector or region. Depending on what kind of
storage medium you're dealing with, reading from disks may involve waiting
for a platter with desired sector to come to the attention of a read/write
head (a thin magnetic sensor used to detect or make changes to magnetic
fields) or peering inside windows and extracting electrons trapped within.
This last sentence is a vivid description of how hard disks and solid-state
drives really work behind the scenes, respectively.
But storage devices are not just meant for reading things for your
enjoyment. Without means of storing new things, it becomes useless.
Depending on the medium you've got, when you save something to a storage
device, the file system in charge of the device will ask the drive
controller to either find a spot on a disk filled with magnets and change
some magnets, or apply heat pressure to dislodge all cells on a block, erase
the block, add new things, and fill the empty block with modified data
(including old bits). You can imagine how tedious this can get, but as far
as your work is concerned, it is safe and sound.
Now imagine you wish to read and write repeatedly on a storage device. The
file system will repeatedly ask the drive hardware to fetch data from
specific regions, and will look for new locations to store changes. On a
hard drive, because there are limited number of heads and it'll take a while
for desired magnetic region to come to attention of one, read speed is slow,
hence increased latency (latency refers to how long you have to wait for
something to happen). When it comes to saving things to HDD's, all the drive
needs to do is tell the read/write head to change some magnets wherever it
wishes, hence data overriding is possible and easy. But operating systems
(rather, file systems) are smarter than that, as we'll see below.
In case of solid-state drives, reading data is simple as looking up the
address (or sector) where the electrons comprising the data you want is
saved (akin to walking down a street grid), so no need to wait for a sensor
to wait for something to happen. This is the reason why solid-state drives
appear to respond fast when reading something. On the other hand, writing or
injecting electrons is very slow because the drive needs to erase the entire
block before writing new data. In other words, just changing a letter in a
document and saving it to an SSD involves a lot of work, hence SSD's are
slower when it comes to writing new things, but because of the underlying
technology in use, it is way faster than hard disks.
As hinted above, file systems are smarter than drive controllers to some
extent. If data is written to a drive, the drive controller will process
whatever it comes along its path. But file systems won't let drive
controllers get away with that: file systems such as NTFS (New Technology
File System) will schedule data writes so it'll have minimal impact on the
lifespan of a storage device. For hard disks, it'll try its best to tell the
drive to store file data in consecutive locations in one big batch, but that
doesn't always work. For SSD's, the file system will ask the drive to
storage new information in different cells so all regions can be used
equally (at least for storing new information; this is called ware
leveling). One way to speed things up is asking the drive to reorganize data
so file fragments can be found in consecutive sectors or trim deleted
regions so fresh information can be written to more blocks (for HDD's and
SSD's, respectively), and this operation itself is tedious and produce bad
results if not done correctly and carefully.

I do understand the above explanation is a bit geeky, but I believe you need
to know some things about how things work. It is also a personal exercise to
refresh my memory on certain computer science topics (I majored in it not
long ago, and my interests were mostly hardware and operating systems, hence
I was sort of naturally drawn to screen reader internals and how it
interacts with system software).
Cheers,
Joseph

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Roger
Stewart
Sent: Friday, January 19, 2018 7:58 AM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

The problem with this discussion is my portable version is on an internal
hard drive. So why is this degrading?

Nothing else on this drive has any trouble and I've checked, and there's no
file system errors nor any fragmenting.


Roger












On 1/19/2018 8:28 AM, Antony Stone wrote:
USB drives do need to be unmounted before removing them, otherwise there
is
the risk of file system corruption. Precisely the same is true for
external
hard drives, floppy disks, or any other writeable medium you can
temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're
considerably
more robust than floppy disks, which is basically what they replaced. You
can
also drop them on the floor with a good deal more confidence of them
working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them
have
plastic caps to put over the contacts or a slider to retract the contacts
into
the body.

My experience is that if they're treated reasonably they work very well.
If
they're mistreated they'll give as many problems as any other mistreated
storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me
their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from the
computer or they get corrupted. They physically fall apart easily. And,
the hardware inside seems to be more vulnerable to static electricity
data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of nvda
will sometimes degrade or get a bit corrupted over time all by itself
while the installed version is always stable as a rock. Does anyone know
why this is and is there any way to prevent this from happening? I use
the portable copy to test a couple add ons and if the portable version
corrupts, it can make it appear that the add on is defective or has a bug
while it really doesn't. Deleting the portable copy and making a new one
will clear it up. I also notice a few functions of nvda either don't
work
at all or nvda gets very sluggish in responsiveness and this all gets
back
to normal after a complete flush and remake of the portable version. As
I
say, this never has happened at all with my installed copy on the same
computer.





Roger


Brian's Mail list account <bglists@...>
 

I disagree, but do agree over dismounting but this is a function of windows caching, not of the vulnerability of ram drives in themselves.
I have noticed though that in windows 7 at least using a command mode batch file to copy to a ram drive, when the batch file exits back to windows the cache is written and all is sweetness and light!

As for static, well unless you are very very unlucky most seem OK to me.
I say this as we use several hundred of them to distribute audio and have had very few failures due to corrupt media.
Brian

bglists@blueyonder.co.uk
Sent via blueyonder.
Please address personal email to:-
briang1@blueyonder.co.uk, putting 'Brian Gaff'
in the display name field.

----- Original Message -----
From: <tonea.ctr.morrow@faa.gov>
To: <nvda@nvda.groups.io>
Sent: Friday, January 19, 2018 2:17 PM
Subject: [nvda] Portable version degrading


A few years back, I had a job for three years where people brought me their files on USB thumb drives. These things are horrible in terms of long-life. The really do have to be unmounted prior to removing from the computer or they get corrupted. They physically fall apart easily. And, the hardware inside seems to be more vulnerable to static electricity data loss than other portable drives, certainly more vulnerable than most computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of nvda will sometimes degrade or get a bit corrupted over time all by itself while the installed version is always stable as a rock. Does anyone know why this is and is there any way to prevent this from happening? I use the portable copy to test a couple add ons and if the portable version corrupts, it can make it appear that the add on is defective or has a bug while it really doesn't. Deleting the portable copy and making a new one will clear it up. I also notice a few functions of nvda either don't work at all or nvda gets very sluggish in responsiveness and this all gets back to normal after a complete flush and remake of the portable version. As I say, this never has happened at all with my installed copy on the same computer.





Roger


Brian's Mail list account <bglists@...>
 

Yes as I say, using them as we do we have had very few issues even in the post and these do not have retractable or covers for end caps either.


Brian

bglists@blueyonder.co.uk
Sent via blueyonder.
Please address personal email to:-
briang1@blueyonder.co.uk, putting 'Brian Gaff'
in the display name field.

----- Original Message -----
From: "Antony Stone" <antony.stone@nvda.open.source.it>
To: <nvda@nvda.groups.io>
Sent: Friday, January 19, 2018 2:28 PM
Subject: Re: [nvda] Portable version degrading


USB drives do need to be unmounted before removing them, otherwise there is
the risk of file system corruption. Precisely the same is true for external
hard drives, floppy disks, or any other writeable medium you can temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're considerably
more robust than floppy disks, which is basically what they replaced. You can
also drop them on the floor with a good deal more confidence of them working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them have
plastic caps to put over the contacts or a slider to retract the contacts into
the body.

My experience is that if they're treated reasonably they work very well. If
they're mistreated they'll give as many problems as any other mistreated
storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from the
computer or they get corrupted. They physically fall apart easily. And,
the hardware inside seems to be more vulnerable to static electricity data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of nvda
will sometimes degrade or get a bit corrupted over time all by itself
while the installed version is always stable as a rock. Does anyone know
why this is and is there any way to prevent this from happening? I use
the portable copy to test a couple add ons and if the portable version
corrupts, it can make it appear that the add on is defective or has a bug
while it really doesn't. Deleting the portable copy and making a new one
will clear it up. I also notice a few functions of nvda either don't work
at all or nvda gets very sluggish in responsiveness and this all gets back
to normal after a complete flush and remake of the portable version. As I
say, this never has happened at all with my installed copy on the same
computer.





Roger
--
#define SIX 1+5
#define NINE 8+1

int main() {
printf("%d\n", SIX * NINE);
}
- thanks to ECB for bringing this to my attention

Please reply to the list;
please *don't* CC me.


Brian's Mail list account <bglists@...>
 

I would disagree really.
No sign of corruption. read my last two messages. Vinyl is mechanical that is why it works. Its low bandwidth and hence more robust and can be seriously damaged and although you can hear the damage often there is enough of the original signal left to make it usable.
This is off topic here.
As a record to cd restorer in my spare time, if you want to talk about his email me.

Brian

bglists@blueyonder.co.uk
Sent via blueyonder.
Please address personal email to:-
briang1@blueyonder.co.uk, putting 'Brian Gaff'
in the display name field.

----- Original Message -----
From: "Rob Hudson" <rob_hudson_3182@gmx.com>
To: <nvda@nvda.groups.io>
Sent: Friday, January 19, 2018 2:44 PM
Subject: Re: [nvda] Portable version degrading


Antony Stone <antony.stone@nvda.open.source.it> wrote:
I've never seen a USB thumb drive fall apart, and I think they're considerably
more robust than floppy disks, which is basically what they replaced. You can
also drop them on the floor with a good deal more confidence of them working
afterwards than if you drop an external hard disk.
I put my portable NVDA installs on S D cards and use a ten dollar USB card reader. The only way to hurt a card like that is to drop it in water, I guess. And most computers nowadays come with card readers built in to them.
If you're willing to pay a little more, you can buy USB flash drives in protective, rubberized or metal housings. These are a great deal sturdier than the cheapies you can get for a few bucks. Not only do those fall apart easily, but they will go corrupt faster. Even if you unmount them using the
"Safey Remove Hardware"
item on windows or the
"umount"
option in Linux. Solid state memory only has a limited number of reads/writes.
The least corruptible data medium I've heard of is vinyl records. I've heard you can actually listen to a vinyl record by spinning it and using a pine needle. They have buried some of our worlds most important speeches and such in the desert on vinyl. I'm not sure what it is about that medium specifically that makes it better suited for long term storage, though.


Brian's Mail list account <bglists@...>
 

The reason I do not use sd cards is their losability for our listeners!
Brian

bglists@blueyonder.co.uk
Sent via blueyonder.
Please address personal email to:-
briang1@blueyonder.co.uk, putting 'Brian Gaff'
in the display name field.

----- Original Message -----
From: <tonea.ctr.morrow@faa.gov>
To: <nvda@nvda.groups.io>
Sent: Friday, January 19, 2018 3:11 PM
Subject: Re: [nvda] Portable version degrading


LOL!



I agree that S.D. cards are a better choice.



As for vinyl, the recording is so big that you can both see and feel it on the media. You can't do that with any traditional computer format-I think that is what give it such stability. Small distortions to the recording don't impede replay.



With regard to burying vinyl recordings in the desert: grains of sand would scratch out the recordings, so I assume you meant they are protectively wrapped and then buried. I still think that might not be such a good way to store vinyl. I remember in the 1970's watching my mom heat a record in the oven and then lay it over a cup to create a vinyl bowl. Unless buried deep enough to not be subject to the heat, the record would be destroyed over time from heat and cold cycle, in my opinion. If buried deep enough to be consistent in temperature, then it becomes accessible to water damage. If you have a link to information on such burials, that would be an interesting read.



All in all though, I agree and think Vinyl has proved itself better at surviving than any computer format. (grinning)



Tonea



-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Rob Hudson
Sent: Friday, January 19, 2018 8:45 AM


I put my portable NVDA installs on S D cards and use a ten dollar USB card reader. The only way to hurt a card like that is to drop it in water, I guess. And most computers nowadays come with card readers built in to them.

If you're willing to pay a little more, you can buy USB flash drives in protective, rubberized or metal housings. These are a great deal sturdier than the cheapies you can get for a few bucks. Not only do those fall apart easily, but they will go corrupt faster. Even if you unmount them using the "Safey Remove Hardware"

item on windows or the

"umount"

option in Linux. Solid state memory only has a limited number of reads/writes.

The least corruptible data medium I've heard of is vinyl records. I've heard you can actually listen to a vinyl record by spinning it and using a pine needle. They have buried some of our worlds most important speeches and such in the desert on vinyl. I'm not sure what it is about that medium specifically that makes it better suited for long term storage, though.


Brian's Mail list account <bglists@...>
 

I don't think it is in fact. I just think its having issues due to other problems perhaps with the drive or some parameter of it.
Brian

bglists@blueyonder.co.uk
Sent via blueyonder.
Please address personal email to:-
briang1@blueyonder.co.uk, putting 'Brian Gaff'
in the display name field.

----- Original Message -----
From: "Roger Stewart" <paganus2@gmail.com>
To: <nvda@nvda.groups.io>
Sent: Friday, January 19, 2018 3:58 PM
Subject: Re: [nvda] Portable version degrading


The problem with this discussion is my portable version is on an internal hard drive. So why is this degrading?

Nothing else on this drive has any trouble and I've checked, and there's no file system errors nor any fragmenting.


Roger












On 1/19/2018 8:28 AM, Antony Stone wrote:
USB drives do need to be unmounted before removing them, otherwise there is
the risk of file system corruption. Precisely the same is true for external
hard drives, floppy disks, or any other writeable medium you can temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're considerably
more robust than floppy disks, which is basically what they replaced. You can
also drop them on the floor with a good deal more confidence of them working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them have
plastic caps to put over the contacts or a slider to retract the contacts into
the body.

My experience is that if they're treated reasonably they work very well. If
they're mistreated they'll give as many problems as any other mistreated
storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from the
computer or they get corrupted. They physically fall apart easily. And,
the hardware inside seems to be more vulnerable to static electricity data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of nvda
will sometimes degrade or get a bit corrupted over time all by itself
while the installed version is always stable as a rock. Does anyone know
why this is and is there any way to prevent this from happening? I use
the portable copy to test a couple add ons and if the portable version
corrupts, it can make it appear that the add on is defective or has a bug
while it really doesn't. Deleting the portable copy and making a new one
will clear it up. I also notice a few functions of nvda either don't work
at all or nvda gets very sluggish in responsiveness and this all gets back
to normal after a complete flush and remake of the portable version. As I
say, this never has happened at all with my installed copy on the same
computer.





Roger



ely.r@...
 

Professor Joseph,
So, first, I will be reading this lecture several time going forward.
However, you do a wonderful job of making geeky things reasonably
comprehensible. I think in part for me is your slight leaning towards
anthropomorphizing file systems, drives and even those little electrons.

One question has to do with defragmenting. Does the process help to increase
the accessing of related pieces of data? Second, does the process extend
drive life to any extent? Last, I promise, I thought I read at some point
that systems had made user invoked defragmentation unnecessary. Be that
true?
Rick the old English teacher who loves Inanimate objects that come to life

Dr. Rick Ely
TVI, Vision Consultant
451 Rocky Hill Road
Florence, MA 01062
&413() 727-3038

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Joseph
Lee
Sent: Friday, January 19, 2018 12:19 PM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

Hi,
It'll depend on what type of drive it is. If it's a traditional hard drive,
it'll degrade as data moves around, creating the need for defragmentation.
This is especially the case when data is repeatedly written and the file
system is asked to find new locations to hold the constantly changing data.
In case of solid-state drives, it'll degrade if the same region is written
repeatedly, as flash memory has limited endurance when it comes to data
reads and writes.
In case of Roger's issue: a possible contributing factor is constant add-on
updates. He uses an add-on that is updated on a regular basis, putting
strain on part of the drive where the add-on bits are stored. Thus, some
drive sectors are repeatedly bombarded with new information, and one way
operating systems will do in this case is move the new data somewhere else
on the drive, potentially fragmenting bits of files (I'll explain in a
moment). Thus one solution is to not test all add-on updates, but that's a
bit risky as Roger is one of the key testers for this add-on I'm talking
about.
Regarding fragmentation and what not: the following is a bit geeky but I
believe you should know about how some parts of a file system (an in
extension, operating systems) works, because I believe it'll help folks
better understand what might be going on:
Storage devices encountered in the wild are typically organized into many
parts, typically into blocks of fixed-length units called "sectors". A
sector is smallest unit of information that the storage device can present
to the outside world, as in how much data can be held on a storage device.
For example, when you store a small document on a hard disk drive (HDD) and
when you wish to open it in Notepad, Windows will ask a module that's in
charge of organizing and interpreting data on a drive (called a file system)
to locate the sector where the document (or magnets or flash cells that
constitute the document data) is stored and bring it out to you. To you, all
you see is the path to the document, but the file system will ask the drive
controller (a small computer inside hard disks and other storage devices) to
fetch data in a particular sector or region. Depending on what kind of
storage medium you're dealing with, reading from disks may involve waiting
for a platter with desired sector to come to the attention of a read/write
head (a thin magnetic sensor used to detect or make changes to magnetic
fields) or peering inside windows and extracting electrons trapped within.
This last sentence is a vivid description of how hard disks and solid-state
drives really work behind the scenes, respectively.
But storage devices are not just meant for reading things for your
enjoyment. Without means of storing new things, it becomes useless.
Depending on the medium you've got, when you save something to a storage
device, the file system in charge of the device will ask the drive
controller to either find a spot on a disk filled with magnets and change
some magnets, or apply heat pressure to dislodge all cells on a block, erase
the block, add new things, and fill the empty block with modified data
(including old bits). You can imagine how tedious this can get, but as far
as your work is concerned, it is safe and sound.
Now imagine you wish to read and write repeatedly on a storage device. The
file system will repeatedly ask the drive hardware to fetch data from
specific regions, and will look for new locations to store changes. On a
hard drive, because there are limited number of heads and it'll take a while
for desired magnetic region to come to attention of one, read speed is slow,
hence increased latency (latency refers to how long you have to wait for
something to happen). When it comes to saving things to HDD's, all the drive
needs to do is tell the read/write head to change some magnets wherever it
wishes, hence data overriding is possible and easy. But operating systems
(rather, file systems) are smarter than that, as we'll see below.
In case of solid-state drives, reading data is simple as looking up the
address (or sector) where the electrons comprising the data you want is
saved (akin to walking down a street grid), so no need to wait for a sensor
to wait for something to happen. This is the reason why solid-state drives
appear to respond fast when reading something. On the other hand, writing or
injecting electrons is very slow because the drive needs to erase the entire
block before writing new data. In other words, just changing a letter in a
document and saving it to an SSD involves a lot of work, hence SSD's are
slower when it comes to writing new things, but because of the underlying
technology in use, it is way faster than hard disks.
As hinted above, file systems are smarter than drive controllers to some
extent. If data is written to a drive, the drive controller will process
whatever it comes along its path. But file systems won't let drive
controllers get away with that: file systems such as NTFS (New Technology
File System) will schedule data writes so it'll have minimal impact on the
lifespan of a storage device. For hard disks, it'll try its best to tell the
drive to store file data in consecutive locations in one big batch, but that
doesn't always work. For SSD's, the file system will ask the drive to
storage new information in different cells so all regions can be used
equally (at least for storing new information; this is called ware
leveling). One way to speed things up is asking the drive to reorganize data
so file fragments can be found in consecutive sectors or trim deleted
regions so fresh information can be written to more blocks (for HDD's and
SSD's, respectively), and this operation itself is tedious and produce bad
results if not done correctly and carefully.

I do understand the above explanation is a bit geeky, but I believe you need
to know some things about how things work. It is also a personal exercise to
refresh my memory on certain computer science topics (I majored in it not
long ago, and my interests were mostly hardware and operating systems, hence
I was sort of naturally drawn to screen reader internals and how it
interacts with system software).
Cheers,
Joseph

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Roger
Stewart
Sent: Friday, January 19, 2018 7:58 AM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

The problem with this discussion is my portable version is on an internal
hard drive. So why is this degrading?

Nothing else on this drive has any trouble and I've checked, and there's no
file system errors nor any fragmenting.


Roger












On 1/19/2018 8:28 AM, Antony Stone wrote:
USB drives do need to be unmounted before removing them, otherwise
there
is
the risk of file system corruption. Precisely the same is true for
external
hard drives, floppy disks, or any other writeable medium you can
temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're
considerably
more robust than floppy disks, which is basically what they replaced.
You
can
also drop them on the floor with a good deal more confidence of them
working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them
have
plastic caps to put over the contacts or a slider to retract the
contacts
into
the body.

My experience is that if they're treated reasonably they work very well.
If
they're mistreated they'll give as many problems as any other
mistreated storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me
their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from
the computer or they get corrupted. They physically fall apart
easily. And, the hardware inside seems to be more vulnerable to
static electricity
data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of
nvda will sometimes degrade or get a bit corrupted over time all by
itself while the installed version is always stable as a rock. Does
anyone know why this is and is there any way to prevent this from
happening? I use the portable copy to test a couple add ons and if
the portable version corrupts, it can make it appear that the add on
is defective or has a bug while it really doesn't. Deleting the
portable copy and making a new one will clear it up. I also notice a
few functions of nvda either don't
work
at all or nvda gets very sluggish in responsiveness and this all gets
back
to normal after a complete flush and remake of the portable version.
As
I
say, this never has happened at all with my installed copy on the
same computer.





Roger


 

Hi,
Defragmentation won't extend drive life. Instead, it makes it a bit faster
for drives to return data you need. For hard drives, once the required
region gets the attention of a read/write head, the head will read
continuously unless told to stop. Ideally, the head can (and should) do this
in one sitting, but sometimes it'll go "mad" if trying to locate fragmented
information all over the drive, particularly if you've edited files and the
drive decided to store the new bits somewhere else.
As for automatic defragmentation, it is controlled by a setting in Optimize
Drives.
As for accessing related data: depends. If the data you need (or a group of
them) is located next to each other, then yes, otherwise the drive will be
searched to locate fragments.
As for calling me a "professor": I don't deserve this title (I don't have a
doctorate in NVDA, let alone computer science or communication studies). Nor
it isn't the first time someone gave me this nickname: many years ago, I was
called "professor" as I seem to know everything about HumanWare BrailleNote,
with some BrailleNote users commenting that I am a Humanware staff when I
was just a high school senior. In terms of NVDA, let's just say that this is
just a small talk from a certified NVDA Expert; perhaps I should record a
tutorial set devoted to NVDA internals.
Cheers,
Joseph

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of
ely.r@comcast.net
Sent: Friday, January 19, 2018 12:34 PM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

Professor Joseph,
So, first, I will be reading this lecture several time going forward.
However, you do a wonderful job of making geeky things reasonably
comprehensible. I think in part for me is your slight leaning towards
anthropomorphizing file systems, drives and even those little electrons.

One question has to do with defragmenting. Does the process help to increase
the accessing of related pieces of data? Second, does the process extend
drive life to any extent? Last, I promise, I thought I read at some point
that systems had made user invoked defragmentation unnecessary. Be that
true?
Rick the old English teacher who loves Inanimate objects that come to life

Dr. Rick Ely
TVI, Vision Consultant
451 Rocky Hill Road
Florence, MA 01062
&413() 727-3038

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Joseph
Lee
Sent: Friday, January 19, 2018 12:19 PM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

Hi,
It'll depend on what type of drive it is. If it's a traditional hard drive,
it'll degrade as data moves around, creating the need for defragmentation.
This is especially the case when data is repeatedly written and the file
system is asked to find new locations to hold the constantly changing data.
In case of solid-state drives, it'll degrade if the same region is written
repeatedly, as flash memory has limited endurance when it comes to data
reads and writes.
In case of Roger's issue: a possible contributing factor is constant add-on
updates. He uses an add-on that is updated on a regular basis, putting
strain on part of the drive where the add-on bits are stored. Thus, some
drive sectors are repeatedly bombarded with new information, and one way
operating systems will do in this case is move the new data somewhere else
on the drive, potentially fragmenting bits of files (I'll explain in a
moment). Thus one solution is to not test all add-on updates, but that's a
bit risky as Roger is one of the key testers for this add-on I'm talking
about.
Regarding fragmentation and what not: the following is a bit geeky but I
believe you should know about how some parts of a file system (an in
extension, operating systems) works, because I believe it'll help folks
better understand what might be going on:
Storage devices encountered in the wild are typically organized into many
parts, typically into blocks of fixed-length units called "sectors". A
sector is smallest unit of information that the storage device can present
to the outside world, as in how much data can be held on a storage device.
For example, when you store a small document on a hard disk drive (HDD) and
when you wish to open it in Notepad, Windows will ask a module that's in
charge of organizing and interpreting data on a drive (called a file system)
to locate the sector where the document (or magnets or flash cells that
constitute the document data) is stored and bring it out to you. To you, all
you see is the path to the document, but the file system will ask the drive
controller (a small computer inside hard disks and other storage devices) to
fetch data in a particular sector or region. Depending on what kind of
storage medium you're dealing with, reading from disks may involve waiting
for a platter with desired sector to come to the attention of a read/write
head (a thin magnetic sensor used to detect or make changes to magnetic
fields) or peering inside windows and extracting electrons trapped within.
This last sentence is a vivid description of how hard disks and solid-state
drives really work behind the scenes, respectively.
But storage devices are not just meant for reading things for your
enjoyment. Without means of storing new things, it becomes useless.
Depending on the medium you've got, when you save something to a storage
device, the file system in charge of the device will ask the drive
controller to either find a spot on a disk filled with magnets and change
some magnets, or apply heat pressure to dislodge all cells on a block, erase
the block, add new things, and fill the empty block with modified data
(including old bits). You can imagine how tedious this can get, but as far
as your work is concerned, it is safe and sound.
Now imagine you wish to read and write repeatedly on a storage device. The
file system will repeatedly ask the drive hardware to fetch data from
specific regions, and will look for new locations to store changes. On a
hard drive, because there are limited number of heads and it'll take a while
for desired magnetic region to come to attention of one, read speed is slow,
hence increased latency (latency refers to how long you have to wait for
something to happen). When it comes to saving things to HDD's, all the drive
needs to do is tell the read/write head to change some magnets wherever it
wishes, hence data overriding is possible and easy. But operating systems
(rather, file systems) are smarter than that, as we'll see below.
In case of solid-state drives, reading data is simple as looking up the
address (or sector) where the electrons comprising the data you want is
saved (akin to walking down a street grid), so no need to wait for a sensor
to wait for something to happen. This is the reason why solid-state drives
appear to respond fast when reading something. On the other hand, writing or
injecting electrons is very slow because the drive needs to erase the entire
block before writing new data. In other words, just changing a letter in a
document and saving it to an SSD involves a lot of work, hence SSD's are
slower when it comes to writing new things, but because of the underlying
technology in use, it is way faster than hard disks.
As hinted above, file systems are smarter than drive controllers to some
extent. If data is written to a drive, the drive controller will process
whatever it comes along its path. But file systems won't let drive
controllers get away with that: file systems such as NTFS (New Technology
File System) will schedule data writes so it'll have minimal impact on the
lifespan of a storage device. For hard disks, it'll try its best to tell the
drive to store file data in consecutive locations in one big batch, but that
doesn't always work. For SSD's, the file system will ask the drive to
storage new information in different cells so all regions can be used
equally (at least for storing new information; this is called ware
leveling). One way to speed things up is asking the drive to reorganize data
so file fragments can be found in consecutive sectors or trim deleted
regions so fresh information can be written to more blocks (for HDD's and
SSD's, respectively), and this operation itself is tedious and produce bad
results if not done correctly and carefully.

I do understand the above explanation is a bit geeky, but I believe you need
to know some things about how things work. It is also a personal exercise to
refresh my memory on certain computer science topics (I majored in it not
long ago, and my interests were mostly hardware and operating systems, hence
I was sort of naturally drawn to screen reader internals and how it
interacts with system software).
Cheers,
Joseph

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Roger
Stewart
Sent: Friday, January 19, 2018 7:58 AM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

The problem with this discussion is my portable version is on an internal
hard drive. So why is this degrading?

Nothing else on this drive has any trouble and I've checked, and there's no
file system errors nor any fragmenting.


Roger












On 1/19/2018 8:28 AM, Antony Stone wrote:
USB drives do need to be unmounted before removing them, otherwise
there
is
the risk of file system corruption. Precisely the same is true for
external
hard drives, floppy disks, or any other writeable medium you can
temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're
considerably
more robust than floppy disks, which is basically what they replaced.
You
can
also drop them on the floor with a good deal more confidence of them
working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them
have
plastic caps to put over the contacts or a slider to retract the
contacts
into
the body.

My experience is that if they're treated reasonably they work very well.
If
they're mistreated they'll give as many problems as any other
mistreated storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me
their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from
the computer or they get corrupted. They physically fall apart
easily. And, the hardware inside seems to be more vulnerable to
static electricity
data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of
nvda will sometimes degrade or get a bit corrupted over time all by
itself while the installed version is always stable as a rock. Does
anyone know why this is and is there any way to prevent this from
happening? I use the portable copy to test a couple add ons and if
the portable version corrupts, it can make it appear that the add on
is defective or has a bug while it really doesn't. Deleting the
portable copy and making a new one will clear it up. I also notice a
few functions of nvda either don't
work
at all or nvda gets very sluggish in responsiveness and this all gets
back
to normal after a complete flush and remake of the portable version.
As
I
say, this never has happened at all with my installed copy on the
same computer.





Roger


ely.r@...
 

Well,
At least Lecturer Joseph, appreciated for his clarity.
Rick

Dr. Rick Ely
TVI, Vision Consultant
451 Rocky Hill Road
Florence, MA 01062
&413() 727-3038

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Joseph
Lee
Sent: Friday, January 19, 2018 3:54 PM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

Hi,
Defragmentation won't extend drive life. Instead, it makes it a bit faster
for drives to return data you need. For hard drives, once the required
region gets the attention of a read/write head, the head will read
continuously unless told to stop. Ideally, the head can (and should) do this
in one sitting, but sometimes it'll go "mad" if trying to locate fragmented
information all over the drive, particularly if you've edited files and the
drive decided to store the new bits somewhere else.
As for automatic defragmentation, it is controlled by a setting in Optimize
Drives.
As for accessing related data: depends. If the data you need (or a group of
them) is located next to each other, then yes, otherwise the drive will be
searched to locate fragments.
As for calling me a "professor": I don't deserve this title (I don't have a
doctorate in NVDA, let alone computer science or communication studies). Nor
it isn't the first time someone gave me this nickname: many years ago, I was
called "professor" as I seem to know everything about HumanWare BrailleNote,
with some BrailleNote users commenting that I am a Humanware staff when I
was just a high school senior. In terms of NVDA, let's just say that this is
just a small talk from a certified NVDA Expert; perhaps I should record a
tutorial set devoted to NVDA internals.
Cheers,
Joseph


-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of
ely.r@comcast.net
Sent: Friday, January 19, 2018 12:34 PM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

Professor Joseph,
So, first, I will be reading this lecture several time going forward.
However, you do a wonderful job of making geeky things reasonably
comprehensible. I think in part for me is your slight leaning towards
anthropomorphizing file systems, drives and even those little electrons.

One question has to do with defragmenting. Does the process help to increase
the accessing of related pieces of data? Second, does the process extend
drive life to any extent? Last, I promise, I thought I read at some point
that systems had made user invoked defragmentation unnecessary. Be that
true?
Rick the old English teacher who loves Inanimate objects that come to life

Dr. Rick Ely
TVI, Vision Consultant
451 Rocky Hill Road
Florence, MA 01062
&413() 727-3038

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Joseph
Lee
Sent: Friday, January 19, 2018 12:19 PM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

Hi,
It'll depend on what type of drive it is. If it's a traditional hard drive,
it'll degrade as data moves around, creating the need for defragmentation.
This is especially the case when data is repeatedly written and the file
system is asked to find new locations to hold the constantly changing data.
In case of solid-state drives, it'll degrade if the same region is written
repeatedly, as flash memory has limited endurance when it comes to data
reads and writes.
In case of Roger's issue: a possible contributing factor is constant add-on
updates. He uses an add-on that is updated on a regular basis, putting
strain on part of the drive where the add-on bits are stored. Thus, some
drive sectors are repeatedly bombarded with new information, and one way
operating systems will do in this case is move the new data somewhere else
on the drive, potentially fragmenting bits of files (I'll explain in a
moment). Thus one solution is to not test all add-on updates, but that's a
bit risky as Roger is one of the key testers for this add-on I'm talking
about.
Regarding fragmentation and what not: the following is a bit geeky but I
believe you should know about how some parts of a file system (an in
extension, operating systems) works, because I believe it'll help folks
better understand what might be going on:
Storage devices encountered in the wild are typically organized into many
parts, typically into blocks of fixed-length units called "sectors". A
sector is smallest unit of information that the storage device can present
to the outside world, as in how much data can be held on a storage device.
For example, when you store a small document on a hard disk drive (HDD) and
when you wish to open it in Notepad, Windows will ask a module that's in
charge of organizing and interpreting data on a drive (called a file system)
to locate the sector where the document (or magnets or flash cells that
constitute the document data) is stored and bring it out to you. To you, all
you see is the path to the document, but the file system will ask the drive
controller (a small computer inside hard disks and other storage devices) to
fetch data in a particular sector or region. Depending on what kind of
storage medium you're dealing with, reading from disks may involve waiting
for a platter with desired sector to come to the attention of a read/write
head (a thin magnetic sensor used to detect or make changes to magnetic
fields) or peering inside windows and extracting electrons trapped within.
This last sentence is a vivid description of how hard disks and solid-state
drives really work behind the scenes, respectively.
But storage devices are not just meant for reading things for your
enjoyment. Without means of storing new things, it becomes useless.
Depending on the medium you've got, when you save something to a storage
device, the file system in charge of the device will ask the drive
controller to either find a spot on a disk filled with magnets and change
some magnets, or apply heat pressure to dislodge all cells on a block, erase
the block, add new things, and fill the empty block with modified data
(including old bits). You can imagine how tedious this can get, but as far
as your work is concerned, it is safe and sound.
Now imagine you wish to read and write repeatedly on a storage device. The
file system will repeatedly ask the drive hardware to fetch data from
specific regions, and will look for new locations to store changes. On a
hard drive, because there are limited number of heads and it'll take a while
for desired magnetic region to come to attention of one, read speed is slow,
hence increased latency (latency refers to how long you have to wait for
something to happen). When it comes to saving things to HDD's, all the drive
needs to do is tell the read/write head to change some magnets wherever it
wishes, hence data overriding is possible and easy. But operating systems
(rather, file systems) are smarter than that, as we'll see below.
In case of solid-state drives, reading data is simple as looking up the
address (or sector) where the electrons comprising the data you want is
saved (akin to walking down a street grid), so no need to wait for a sensor
to wait for something to happen. This is the reason why solid-state drives
appear to respond fast when reading something. On the other hand, writing or
injecting electrons is very slow because the drive needs to erase the entire
block before writing new data. In other words, just changing a letter in a
document and saving it to an SSD involves a lot of work, hence SSD's are
slower when it comes to writing new things, but because of the underlying
technology in use, it is way faster than hard disks.
As hinted above, file systems are smarter than drive controllers to some
extent. If data is written to a drive, the drive controller will process
whatever it comes along its path. But file systems won't let drive
controllers get away with that: file systems such as NTFS (New Technology
File System) will schedule data writes so it'll have minimal impact on the
lifespan of a storage device. For hard disks, it'll try its best to tell the
drive to store file data in consecutive locations in one big batch, but that
doesn't always work. For SSD's, the file system will ask the drive to
storage new information in different cells so all regions can be used
equally (at least for storing new information; this is called ware
leveling). One way to speed things up is asking the drive to reorganize data
so file fragments can be found in consecutive sectors or trim deleted
regions so fresh information can be written to more blocks (for HDD's and
SSD's, respectively), and this operation itself is tedious and produce bad
results if not done correctly and carefully.

I do understand the above explanation is a bit geeky, but I believe you need
to know some things about how things work. It is also a personal exercise to
refresh my memory on certain computer science topics (I majored in it not
long ago, and my interests were mostly hardware and operating systems, hence
I was sort of naturally drawn to screen reader internals and how it
interacts with system software).
Cheers,
Joseph

-----Original Message-----
From: nvda@nvda.groups.io [mailto:nvda@nvda.groups.io] On Behalf Of Roger
Stewart
Sent: Friday, January 19, 2018 7:58 AM
To: nvda@nvda.groups.io
Subject: Re: [nvda] Portable version degrading

The problem with this discussion is my portable version is on an internal
hard drive. So why is this degrading?

Nothing else on this drive has any trouble and I've checked, and there's no
file system errors nor any fragmenting.


Roger












On 1/19/2018 8:28 AM, Antony Stone wrote:
USB drives do need to be unmounted before removing them, otherwise
there
is
the risk of file system corruption. Precisely the same is true for
external
hard drives, floppy disks, or any other writeable medium you can
temporarily
attach to a computer.

I've never seen a USB thumb drive fall apart, and I think they're
considerably
more robust than floppy disks, which is basically what they replaced.
You
can
also drop them on the floor with a good deal more confidence of them
working
afterwards than if you drop an external hard disk.

Yes, they're vulnerable to static electricity; that's why most of them
have
plastic caps to put over the contacts or a slider to retract the
contacts
into
the body.

My experience is that if they're treated reasonably they work very well.
If
they're mistreated they'll give as many problems as any other
mistreated storage medium.


Antony.

On Friday 19 January 2018 at 15:17:36, tonea.ctr.morrow@faa.gov wrote:

A few years back, I had a job for three years where people brought me
their
files on USB thumb drives. These things are horrible in terms of
long-life. The really do have to be unmounted prior to removing from
the computer or they get corrupted. They physically fall apart
easily. And, the hardware inside seems to be more vulnerable to
static electricity
data
loss than other portable drives, certainly more vulnerable than most
computers.



I would think that would be the problem.



Tonea



-----Original Message-----

I've noticed over the past couple years that my portable install of
nvda will sometimes degrade or get a bit corrupted over time all by
itself while the installed version is always stable as a rock. Does
anyone know why this is and is there any way to prevent this from
happening? I use the portable copy to test a couple add ons and if
the portable version corrupts, it can make it appear that the add on
is defective or has a bug while it really doesn't. Deleting the
portable copy and making a new one will clear it up. I also notice a
few functions of nvda either don't
work
at all or nvda gets very sluggish in responsiveness and this all gets
back
to normal after a complete flush and remake of the portable version.
As
I
say, this never has happened at all with my installed copy on the
same computer.





Roger