[Gllug] [OT] Re: cheap disk source

[John Hearns]

James Roberts wrote:
>
> 
> John,
> 
> may I ask: what are your uptime views on RAID6 no hot spare -vs- RAID5 + 
> hot spare?

I do not have views on uptime I'm afraid.

What RAID 6 is intended for is to cope with double disk failure.
If your RAID 5 set loses a disk it will start to rebuild onto a hot 
spare (assuming there is one). During that time window if you lose 
another disk, or there are bad blocks on the spare, then you can lose data.

Raid 6 has a performance penalty wrt Raid 5


Of course, if you have the requirement and the budget (ie twice the 
number of disks!) there is RAID 51 - mirrored RAID 5 sets.
You pays your money and you takes your choice.


-- 
      John Hearns
      Senior HPC Engineer
      Streamline Computing,
      The Innovation Centre, Warwick Technology Park,
      Gallows Hill, Warwick CV34 6UW
      Office: 01926 623130 Mobile: 07841 231235
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