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On Monday 23 July 2007, maxim wexler wrote: |
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> > Which will destroy your flash device in as little as |
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> > a couple of months |
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> > (voice of experience here), and it probably the |
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> > reason the option was |
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> > removed. |
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> |
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> Ulp! Here's my line from fstab: |
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> |
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> /dev/sdb1 /usb auto |
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> noauto,user,rw,exec,sync 0 0 |
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> |
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> Copied from a forum somewhere. For use of my mp3 |
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> player and digi-camera, both formatted vfat. Does |
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> 'noauto' cancel 'sync'? This way un/mounting must be |
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> done manually. Does that spare me? |
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|
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No. read 'man mount' |
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|
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In a nutshell, noauto means the device will not be automativcally |
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mounted at boot time when the init script runs. |
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sync is a different beast - it means that "All I/O to the file system |
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should be done synchronously." That means that when the kernel say to |
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write to the device, it does get written, and not cached somewhere. |
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Caching it and returning the correct result to indicate that the write |
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was completed would be of course 'async' |
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|
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> I haven't noticed any problems yet. Are you saying |
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> that the damage is incremental, that it accumulates |
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> until a certain point is reached and the device is |
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> kaput? |
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|
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It's only a matter of time and relates to how flash devices work. After |
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many many writes to the same storage cell, it degrades. The good ones |
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are rated to about 100,000 writes per cell. The cheap and nasty ones |
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can be as low as 10,000 writes. You would be amazed how quickly 50,000 |
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writes can happen to the same cell when used as swap for example |
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|
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This is a known issue with flash devices. The correct solution is to |
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ONLY write to the device once you are ready to unmount it. Treat it |
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much like a CD and you'll be OK |
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|
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alan |
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|
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-- |
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Optimists say the glass is half full, |
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Pessimists say the glass is half empty, |
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Developers say wtf is the glass twice as big as it needs to be? |
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|
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Alan McKinnon |
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alan at linuxholdings dot co dot za |
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+27 82, double three seven, one nine three five |
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-- |
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