On 13/09/13 22:12, Marcel Meckel wrote:
> Hi there,
>
> The newly ordered machine spec is as follows:
>
>    25x 600GB 2.5" SAS 10k rpm 6G DP disks
>
> My preferred RAID config would be RAID6 (HP calls it ADG,
> Advanced Data Guard) over 24 disks + one disk as hot spare.

So if 3 out of 23 disks fail in less time that it takes to complete a
rebuild, then you will lose 100% of your data.

Perhaps you might consider dividing that into two, and making at least 2
x RAID6 arrays with 11 drives each, and keep 2 x hot spares, then
combine them as a RAID0 (linear) so you can easily expand later as needed.

PS, suggestion is based on reading advice given on the linux-raid list,
where they usually seem to suggest no more than 8 to 10 drives per RAID6
array (from memory).

I think it is based on reducing the chance of multiple disk failures on
a single array with a large number of disks.

Regards,
Adam

-- 
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Website Managers
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-- 
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