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On Tue, 08 Jan 2013 20:06:25 +0100 |
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Florian Philipp <lists@×××××××××××.net> wrote: |
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> Am 08.01.2013 18:35, schrieb Volker Armin Hemmann: |
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> > Am Dienstag, 8. Januar 2013, 08:27:51 schrieb Florian Philipp: |
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> >> Am 08.01.2013 00:20, schrieb Alan McKinnon: |
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> >>> On Mon, 07 Jan 2013 21:11:35 +0100 |
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> >>> |
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> >>> Florian Philipp <lists@×××××××××××.net> wrote: |
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> >>>> Hi list! |
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> >>>> |
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> >>>> I have a use case where I am seriously concerned about bit rot |
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> >>>> [1] and I thought it might be a good idea to start looking for |
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> >>>> it in my own private stuff, too. |
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> >> |
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> >> [...] |
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> >> |
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> >>>> [1] http://en.wikipedia.org/wiki/Bit_rot |
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> [...] |
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> >>> If you mean disk file corruption, then doing it file by file is a |
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> >>> colossal waste of time IMNSHO. You likely have >1,000,000 files. |
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> >>> Are you really going to md5sum each one daily? Really? |
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> >> |
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> >> Well, not daily but often enough that I likely still have a valid |
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> >> copy as a backup. |
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> > |
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> > and who guarantees that the backup is the correct file? |
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> > |
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> |
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> That's why I wanted to store md5sum (or sha2sums). |
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Watch out for circular problems - you will likely store the md5sum on |
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the same medium type you are trying to validate. Which means the md5sum |
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is just as unreliable as the data itself :-) |
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Interesting factoid: we long since passed the point where there is a |
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statistical good chance of cosmic rays flipping bits in a RAID that is |
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being rebuilt *before* the rebuild is complete. Usually we all just |
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pretend it's not like this and we'll get lucky. usually this works out |
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fine because we are lucky |
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-- |
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Alan McKinnon |
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alan.mckinnon@×××××.com |
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