I understand all the RAID levels very well, hence the question, if not direct enough.
The question was intended to ask about RAID5/6 reliability re: very large disks. Does the rebuild time/number of IOs required vs the UER (unrecoverable error rate) of the drives, with 2.4TB drives, create undue risk? I could not find a spec on the 2.4TB SAS drives rate; 10^16? 10^15?
What's HPE's guidance on RAID5/6 on multi-TB HDDs with many spindles? Where's the edge of the cliff?
And perhaps my terminology was inexact. I'm looking to have both controllers actively working. Each controller owning a virtual volume with 2 disk groups:
- 2 x 800GB SSD performance tier disk group
- 8 x 2.4TB HDD standard tier disk group
So, is that 2 pools, each of one vVol comprising 2 DG each?
If I have a spare SSD and HDD (I noted the spares) then wouldn't the MSA not bleed out the pages on an SSD failure because it would have a spare to incorporate? Or is there no sparing for SSDs?
