question on vinum
cswiger at mac.com
Wed Oct 27 05:05:17 PDT 2004
Mikhail P. wrote:
> On Wednesday 27 October 2004 05:33, secmgr wrote:
[ ... ]
>> If you want to do that, then you want raid5. If either a concat or
>> stripe set looses a drive, the data will need to be restored.
> Are there known methods/techniques to restore data from failed concat or
> stripe volumes?
Certainly. It's known as "taking a backup", perhaps to a tape drive or some
other form of storage. If you don't have a backup, and you lose a disk in a
RAID-0 config, you will effectively lose all of the data.
[ ... ]
> Does striping require an additional drive too?
> Or it is very similar to
> concat, except for it stores data across all the spindles?
Yes, that's right.
> Does it also mean that it is harder to recover stripped volume?
The question isn't well-phrased: you can't recover data from either if you
lose a drive.
> As for raid5 - it requires an additional drive. Are there any requirements for
> the drive? E.g. would it work as having 3 x 200GB for stripe + additional
> 20GB drive that will be used for control blocks?
No. All of the drives need to be the same size. With RAID-5, which drive is
used to hold parity data rotates on a stripe-by-stripe basis to balance out
> And what happens here if
> 20GB drive fails - will I be able to rebuild it and continue using raid?
You can rebuild a RAID-5 volume if a single drive fails without losing data.
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