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>> http://blog.open-e.com/why-a-hot-spare-hard-disk-is-a-bad-idea/ |
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>> |
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>> "Based on our long years of experience we have learned that during a |
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>> RAID rebuild the probability of an additional drive failure is quite |
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>> high – a rebuild is stressful on the existing drives." |
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> |
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> This is NOT true on a RAID 10... a rebuild is only stressful on the other |
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> drive in the mirrored pair, not the other drives. |
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> |
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> But, it is true for that one drive. |
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|
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Why wouldn't it be true of RAID 10? Each drive only has one mirror, |
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so if a drive fails, its only mirror will be stressed by the rebuild |
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won't it? |
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|
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> That said, it would be nice is the auto rebuild could be scripted such that |
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> a backup could be triggered and the auto-rebuild queued until the backup was |
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> complete. |
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> |
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> But, here is the problem there... a backup will stress the drive almost as |
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> much as the rebuild, because all the rebuild does is read/copy the contents |
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> of the one drive to the other one (ie, it re-mirrors). |
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> |
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>> Instead, how about a 6-drive RAID 10 array with no hot spare? My |
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>> guess is this would mean much greater fault-tolerance both overall and |
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>> during the rebuild process (once a new drive is swapped in). That |
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>> would mean not only potentially increased uptime but decreased |
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>> monitoring responsibility. |
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> |
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> I would still prefer a hot spare to not... in the real world, it has saved |
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> me exactly 3 out of 3 times... |
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|
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You would prefer 4-drive RAID 10 plus a hot spare to 6-drive RAID 10? |
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Isn't 6-drive RAID 10 superior in every way except for cost (1 extra |
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drive)? |
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|
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- Grant |
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