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  • Time to abandon large mechanical hard drives?

    From Alexander Suvorov@21:1/5 to All on Fri Jul 8 16:29:42 2016
    Hello, 7.
    On 7/8/16 2:59 PM you wrote:

    Time to abandon large mechanical hard drives? --------------------------------------------- Time now me thinks to
    ditch mechanical hard drives and go full on with SSDs for big
    storage. The only thing standing in the way is high price SSD
    storage. Also the effort to make larger commercial SSDs a little
    weak.

    High price is onne thing, but don't SSDs also have a significantly
    shorter lifespan (I mean the number of re-write cycles before
    degradation starts) compared to HDDs? Or am I stuck in the past and this problem has already been resolved?

    --
    Best regards! Alexander.
    https://www.linuxcounter.net/user/495771

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  • From Jeff Jonas@21:1/5 to All on Sun Jul 10 04:47:41 2016
    Time to abandon large mechanical hard drives?

    Many (most?) Solid State Drives DO NOT RETAIN DATA FOREVER!
    NOT for offline backups!

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  • From David Brown@21:1/5 to Alexander Suvorov on Mon Jul 11 09:33:09 2016
    On 08/07/16 15:29, Alexander Suvorov wrote:
    Hello, 7.
    On 7/8/16 2:59 PM you wrote:

    Time to abandon large mechanical hard drives? --------------------------------------------- Time now me thinks to
    ditch mechanical hard drives and go full on with SSDs for big
    storage. The only thing standing in the way is high price SSD
    storage. Also the effort to make larger commercial SSDs a little
    weak.

    High price is onne thing, but don't SSDs also have a significantly
    shorter lifespan (I mean the number of re-write cycles before
    degradation starts) compared to HDDs? Or am I stuck in the past and this problem has already been resolved?


    That only applies to old, small or very low-end SSD's. If you have a
    mid-range consumer SSD with 200GB+ of size, there is no realistic
    workload that could ever come close to wearing it out.

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  • From David Brown@21:1/5 to Jeff Jonas on Mon Jul 11 09:31:17 2016
    On 10/07/16 10:47, Jeff Jonas wrote:
    Time to abandon large mechanical hard drives?

    Many (most?) Solid State Drives DO NOT RETAIN DATA FOREVER!
    NOT for offline backups!


    If you write /vast/ amounts of data (we are talking PB for a modern SSD
    - re-writing the entire disk a few thousand times) then store it at high temperature, then you might get problems with retention after as little
    as a year.

    But if you write more sane amounts of data, and store the archived SSD
    at sensible temperatures (like room temperature), it will retain all its
    data for a good many years.

    For comparison, a worn mechanical disk always has the risk of simply
    failing mechanically if it has been left unused and unpowered for years.

    In either case, multiple copies of your archive data are advisable. But
    SSD's are not worse than HD's for the purpose - they are just different.

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  • From Charles Lindsey@21:1/5 to David Brown on Mon Jul 16 11:20:16 2018
    On 11/07/16 08:33, David Brown wrote:
    On 08/07/16 15:29, Alexander Suvorov wrote:

    That only applies to old, small or very low-end SSD's. If you have a mid-range consumer SSD with 200GB+ of size, there is no realistic
    workload that could ever come close to wearing it out.

    Well I have a box controlling the heating in our Church. Its SSD is
    actually a USB stick (about 10 years old now), but the stuff on it
    changes rarely (e.g. when I upgrade the software) and I carefully chose
    a web server (Appweb) that deliberately keeps its state information in
    RAM. So I hope the box will continue to run for many years (though
    things might break for other reasons in Jan. 2038).

    BUT there are a few kilobytes of data that are changing all the time
    (e.g. a record of temperature changes over the last month, and the
    schedule of upcoming heating requirements). I did not want to trust
    Flash memory for that, so I installed a 128 kB EEPROM (which claimed it
    could be overwritten a million times before wearing out).

    Was this a good move? Recently, I observed a lot of random read failures
    (which usually corrected themselves when you re-read the same address).
    Now it may be due to the hot weather (the room housing the box has
    regularly been at 30 degrees Celcius over this last month - maybe it
    will be OK when the weather gets cooler).

    Should I be worried? Data is written to it a byte at a time, whenever
    the temperature in one of the 4 zones changes by 0.1 degree. It is not
    clear whether, behind the scenes, it overwrites a full 12b-byte block
    when you try to overwrite a single byte.

    What alternative options do I have?

    --
    Charles H. Lindsey ---------At my New Home, still doing my own
    thing-----------
    Tel: +44 161 488 1845 Web:
    http://www.cs.man.ac.uk/~chl
    Email: [email protected] Snail: 40 SK8 5BF, U.K.
    PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14
    A4 AB A5

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