Defragment flash drive on Vista

Robert Pendell wrote:
> Michael Lanier wrote:
>> XP allows me to defragment drives other than my hard drive. I am
>> unable to find that capability on my Vista. Is it available and how
>> would I access it.
>> Thanks.
>>
>> url:http://www.ureader.com/gp/1279-1.aspx
>
> Never defragment a flash drive. It will shorten the lifespan of the
> drive and there will be no benefit to doing this.
>

I'll add that if you want to "defragment" a drive then do this by first
copying the files off of the drive, doing a quick format, then copying
them back. When written they will be done so in sequential order and
the files will end up together. with no fragmentation.

--
Robert Pendell
shinji.TakeThisOut@elite-systems.org

"A perfect world is one of chaos."

Thawte Web of Trust Notary
CAcert Assurer
 >> Stay informed about: Defragment flash drive on Vista 

"Bill in Co." <not_really_here.TakeThisOut@earthlink.net> wrote in message
news:%23M7umMhsIHA.1768@TK2MSFTNGP03.phx.gbl...
> M.I.5¾ wrote:
>> "Bill in Co." <not_really_here.TakeThisOut@earthlink.net> wrote in message
>> news:OIyM5SOsIHA.1236@TK2MSFTNGP02.phx.gbl...
>>> Updated below...
>>>
>>> Bill in Co. wrote:
>>>> M.I.5¾ wrote:
>>>>> "Michael Lanier" <jamaica.TakeThisOut@charter.net> wrote in message
>>>>> news:0a85f12c8e9f42d79f10e0b727be1849@newspe.com...
>>>>>> XP allows me to defragment drives other than my hard drive. I am
>>>>>> unable
>>>>>> to find that capability on my Vista. Is it available and how would I
>>>>>> access it.
>>>>>> Thanks.
>>>>>>
>>>>>> url:http://www.ureader.com/gp/1279-1.aspx
>>>>>
>>>>> Under any operating system, I would be reluctant to defragment any
>>>>> FLASH
>>>>> memory drive for 2 reasons.
>>>>>
>>>>> 1. The multiple file fragment shifts that are required during any
>>>>> defragment
>>>>> operation are going to severely tax the limited life of the FLASH
>>>>> memory
>>>>> blocks (limited to an *average* of 1000 erase/write cycles).
>>>>
>>>> Is that documented somewhere? Or does it vary all over the place?
>>>
>>> Actually, I just spent a bit of time looking this lifetime thing up now,
>>> and I'm seeing articles mentioning 10,000 - 100,000 erase/write cycles,
>>> not 1000. So while it's true that defragging will tap into this a
>>> bit,
>>> occasionally doing it probably wouldn't be all that harmful (although
>>> there isn't much point).
>>
>> There is confusion because there are 2 lives associated with FLASH memory
>> cells. The regular memory blocks (the ones that actually hold the data)
>> are
>> lifed for an average of 1000 erase/write cycles.
>
> Do you have a site for this low figure today? I'm not finding it.
>
>> These blocks are utilised
>> on a rotating basis to ensure that the least recently erased and written
>> block is the next one to be erased and written (this is called 'wear
>> levelling' and is designed to extend the life as far as possible).
>
> Right. I've read that. But again, from the user's point of view, I
> don't think it comes down to 1000 erase/write cycles. (The figures
> I've been seeing are 10 to 100 times that, at least as I recall, even for
> this - 10,000 - 100,000).
>
>> However,
>> every FLASH memory device also has a block that holds the houskeeping
>> data
>> such as the FATs and in which block the data is actually held. This
>> block
>> has to have a much greater life because it has to be completely erased
>> and
>> rewritten every time the memory is altered. It is this block that is
>> lifed
>> for 100,000 erase write cycles.
>
> Or was, in the past?
>
>> The architecture of FLASH memory cells is
>> designed to keep the cost down as much as possible, and it is a fact of
>> these devices that if one block fails (be it data or housekeeping), the
>> whole
>> memory device is rendered useless.
>
> But I think they have some recovery algorithms built into the UFD to
> handle some of these potential contingencies.
>
>> Fortunately it is only the erase/write that is life limited. If the
>> memory
>> can be written and verified, then the read life is, thankfully,
>> relatively
>> infinite. That makes this type of memory ideal for holding device
>> firmware
>> that may be updated relatively infrequently, but its use in USB thumb
>> drives, though not ideal, is considered acceptable because the low cost
>> of
>> the memory means that the drives can be cheaply replaced when a failure
>> does
>> occur. I have got through several.
>>
>> If you have ever watched the graphic representation of file fragment
>> movements that occur when a drive is defragmented, you will appreciate
>> that
>> a FLASH drive will get one hell of workout as the defragmentation
>> proceeds.
>

We use these memories to hold firmware in avionic equipment. The life data
is freely available in the manufacturer's reliability data. Airborne
approved devices don't have any longer life than the more normal FLASH
memory devices. The life doesn't cause any problem on normal service
equipment because we have to verify the load after writing. However, on
development equipment the FLASH device can often fail with the frequent
rewrites that occur (often the whole device as firmware changes).

I was going to link to some data or information, but the internet is down
here at present.
 >> Stay informed about: Defragment flash drive on Vista 

"Bill in Co." <not_really_here.TakeThisOut@earthlink.net> wrote in message
news:%23M7umMhsIHA.1768@TK2MSFTNGP03.phx.gbl...
> M.I.5¾ wrote:
>> "Bill in Co." <not_really_here.TakeThisOut@earthlink.net> wrote in message
>> news:OIyM5SOsIHA.1236@TK2MSFTNGP02.phx.gbl...
>>> Updated below...
>>>
>>> Bill in Co. wrote:
>>>> M.I.5¾ wrote:
>>>>> "Michael Lanier" <jamaica.TakeThisOut@charter.net> wrote in message
>>>>> news:0a85f12c8e9f42d79f10e0b727be1849@newspe.com...
>>>>>> XP allows me to defragment drives other than my hard drive. I am
>>>>>> unable
>>>>>> to find that capability on my Vista. Is it available and how would I
>>>>>> access it.
>>>>>> Thanks.
>>>>>>
>>>>>> url:http://www.ureader.com/gp/1279-1.aspx
>>>>>
>>>>> Under any operating system, I would be reluctant to defragment any
>>>>> FLASH
>>>>> memory drive for 2 reasons.
>>>>>
>>>>> 1. The multiple file fragment shifts that are required during any
>>>>> defragment
>>>>> operation are going to severely tax the limited life of the FLASH
>>>>> memory
>>>>> blocks (limited to an *average* of 1000 erase/write cycles).
>>>>
>>>> Is that documented somewhere? Or does it vary all over the place?
>>>
>>> Actually, I just spent a bit of time looking this lifetime thing up now,
>>> and I'm seeing articles mentioning 10,000 - 100,000 erase/write cycles,
>>> not 1000. So while it's true that defragging will tap into this a
>>> bit,
>>> occasionally doing it probably wouldn't be all that harmful (although
>>> there isn't much point).
>>
>> There is confusion because there are 2 lives associated with FLASH memory
>> cells. The regular memory blocks (the ones that actually hold the data)
>> are
>> lifed for an average of 1000 erase/write cycles.
>
> Do you have a site for this low figure today? I'm not finding it.
>
>> These blocks are utilised
>> on a rotating basis to ensure that the least recently erased and written
>> block is the next one to be erased and written (this is called 'wear
>> levelling' and is designed to extend the life as far as possible).
>
> Right. I've read that. But again, from the user's point of view, I
> don't think it comes down to 1000 erase/write cycles. (The figures
> I've been seeing are 10 to 100 times that, at least as I recall, even for
> this - 10,000 - 100,000).
>

FLASH memories that are used like disc drives (like USB thumb drives) rotate
the blocks. So that whereas each block may have a 1000 erase/write life,
the overall memory has a much longer life because the actual wear is shared
out. Thus the memory can have a practical life much longer than the
individual block life. But the way in which the memory is used can
influence that. We wear out FLASH memories quite quickly, because we have
to write firmware back into the whole memory (thus subjecting all the blocks
to an erase/write cycle in one swoop). Since the *average* life of a block
is 1000 cycles, in any memory device, on average half the blocks have a
shorter life, and there is therefore a good chance that an individual memory
device will contain such blocks. Not so infrequently a memory is
encountered that has a very short life indeed.
 >> Stay informed about: Defragment flash drive on Vista 

"M.I.5¾" <no.one.RemoveThis@no.where.NO_SPAM.co.uk> wrote in message
news:4827ecc3$1_1@glkas0286.greenlnk.net...
>
> "Bill in Co." <not_really_here.RemoveThis@earthlink.net> wrote in message
> news:%23M7umMhsIHA.1768@TK2MSFTNGP03.phx.gbl...
>> M.I.5¾ wrote:
>>> "Bill in Co." <not_really_here.RemoveThis@earthlink.net> wrote in message
>>> news:OIyM5SOsIHA.1236@TK2MSFTNGP02.phx.gbl...
>>>> Updated below...
>>>>
>>>> Bill in Co. wrote:
>>>>> M.I.5¾ wrote:
>>>>>> "Michael Lanier" <jamaica.RemoveThis@charter.net> wrote in message
>>>>>> news:0a85f12c8e9f42d79f10e0b727be1849@newspe.com...
>>>>>>> XP allows me to defragment drives other than my hard drive. I am
>>>>>>> unable
>>>>>>> to find that capability on my Vista. Is it available and how would
>>>>>>> I
>>>>>>> access it.
>>>>>>> Thanks.
>>>>>>>
>>>>>>> url:http://www.ureader.com/gp/1279-1.aspx
>>>>>>
>>>>>> Under any operating system, I would be reluctant to defragment any
>>>>>> FLASH
>>>>>> memory drive for 2 reasons.
>>>>>>
>>>>>> 1. The multiple file fragment shifts that are required during any
>>>>>> defragment
>>>>>> operation are going to severely tax the limited life of the FLASH
>>>>>> memory
>>>>>> blocks (limited to an *average* of 1000 erase/write cycles).
>>>>>
>>>>> Is that documented somewhere? Or does it vary all over the place?
>>>>
>>>> Actually, I just spent a bit of time looking this lifetime thing up
>>>> now,
>>>> and I'm seeing articles mentioning 10,000 - 100,000 erase/write cycles,
>>>> not 1000. So while it's true that defragging will tap into this a
>>>> bit,
>>>> occasionally doing it probably wouldn't be all that harmful (although
>>>> there isn't much point).
>>>
>>> There is confusion because there are 2 lives associated with FLASH
>>> memory
>>> cells. The regular memory blocks (the ones that actually hold the data)
>>> are
>>> lifed for an average of 1000 erase/write cycles.
>>
>> Do you have a site for this low figure today? I'm not finding it.
>>
>>> These blocks are utilised
>>> on a rotating basis to ensure that the least recently erased and written
>>> block is the next one to be erased and written (this is called 'wear
>>> levelling' and is designed to extend the life as far as possible).
>>
>> Right. I've read that. But again, from the user's point of view,
>> I don't think it comes down to 1000 erase/write cycles. (The figures
>> I've been seeing are 10 to 100 times that, at least as I recall, even for
>> this - 10,000 - 100,000).
>>
>>> However,
>>> every FLASH memory device also has a block that holds the houskeeping
>>> data
>>> such as the FATs and in which block the data is actually held. This
>>> block
>>> has to have a much greater life because it has to be completely erased
>>> and
>>> rewritten every time the memory is altered. It is this block that is
>>> lifed
>>> for 100,000 erase write cycles.
>>
>> Or was, in the past?
>>
>>> The architecture of FLASH memory cells is
>>> designed to keep the cost down as much as possible, and it is a fact of
>>> these devices that if one block fails (be it data or housekeeping), the
>>> whole
>>> memory device is rendered useless.
>>
>> But I think they have some recovery algorithms built into the UFD to
>> handle some of these potential contingencies.
>>
>>> Fortunately it is only the erase/write that is life limited. If the
>>> memory
>>> can be written and verified, then the read life is, thankfully,
>>> relatively
>>> infinite. That makes this type of memory ideal for holding device
>>> firmware
>>> that may be updated relatively infrequently, but its use in USB thumb
>>> drives, though not ideal, is considered acceptable because the low cost
>>> of
>>> the memory means that the drives can be cheaply replaced when a failure
>>> does
>>> occur. I have got through several.
>>>
>>> If you have ever watched the graphic representation of file fragment
>>> movements that occur when a drive is defragmented, you will appreciate
>>> that
>>> a FLASH drive will get one hell of workout as the defragmentation
>>> proceeds.
>>
>
> We use these memories to hold firmware in avionic equipment. The life
> data is freely available in the manufacturer's reliability data. Airborne
> approved devices don't have any longer life than the more normal FLASH
> memory devices. The life doesn't cause any problem on normal service
> equipment because we have to verify the load after writing. However, on
> development equipment the FLASH device can often fail with the frequent
> rewrites that occur (often the whole device as firmware changes).
>
> I was going to link to some data or information, but the internet is down
> here at present.
>

Just looked it up in a paper catalogue and the wording from NEC is rather
more vague. They guarantee the life of block 0 (the houskeeping block) for
100,000 erase write cycles. However, they specifically state that they make
no guarantee as to the life of any other blocks but that they have a typical
average life of 1000 erase/write cycles.
 >> Stay informed about: Defragment flash drive on Vista