On Wed, 28 Nov 2001, Howard Lowndes wrote:
> If I have a RAID 5 set of 3 drives, and 1 drive fails, does that screw up
> my data or will it still run on 2 drives after it has sorted itself out.
Nope. Your data will survive on 2 drives. Three is the minimum drive
number for a raid 5 set. If a drive failure when you've only got 3 drives
lost data, then it couldn't legitimately be called raid. However, you run
huge risks {see point 2 below} if you don't replace it immediately.
> Must I be including a hot spare? I know I should, but must I?
Of course not. However, there are advantages to doing so.
1) You are guaranteed matched drives. This might sound trivial, but if you
buy three drives and run them for, say, three years, have you any idea
what your chances are of replacing one which fails?
2) The onus of immediately replacing any failed drive {in a three drive
set} is reduced. Your hot spare takes over, and you've still got a valid
raid 5 set with full recoverability. You can withstand _two_ drive
failures in short order - and anyone who thinks that's unlikely hasn't
worked with large raid sets much. :-)
DaZZa
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