we have new VNX5300 system (only DPE for now) with 15 3,5'' disks:
10x600GB 10k SAS (0-3 vault disks) and 5x2TB NL-SAS.
We are in doubt which RAID level is suitable for these 5 NL-SAS disks.
EMC recommends RAID 6 level for high capacity disks, but as we have odd number
of disks the only option is to create RAID 6 on 4 disks and leave 5th disk as a hot spare.
In this situation there is only about 3,6TB of usable space compared with ~9TB total raw space.
On the other hand, we could create RAID 5 (3+1) with first four disks and designate 5th disk as
a hot spare. The result is ~5,4TB of usable space.
What you think, which is better option of these two?
Of course, if anyone have better idea it would be considered !!
Thanks in advance,