2011-05-27 10:48 AM
Hello all, currently we have 3 hosts but we're trimming down to 2. I have had another vendor do an ESXTOP trace for 1 day on our infrastructure and they came up with about 600IOPS average through out the day with 50/50 read write. Ironically the bulk of our oepration is 300IOPS but a syslog server demands 300 itself.
My question is that if I want 6-8 useable TB of storage using RAID DP, what combination of disks should I get? My reseller has been taking a long time getting this answer or assistance from netapp so i'm going to do some legwork myself.
A comparable correctly sized equalogic to our needs would be PS4000X 16x600gb 10k SAS drives. I'm wondering how this translates into a FAS 2040.
2011-06-02 01:54 PM
the thumb rule is, for reading you have the IOPS of the individual disks, and for write, there is a RAID penalty, in case of RAID-DP it is 2.
The calculation is (iops*read%) + (iops*write%*2)
(600 * 0,5) + (600 * 0,5 * 2) = 900 IOPS
so the 600 IOPS is 900 IOPS on the array. Now you need to divide by disk IOPS: 15krpm is 175/disk, 10krpm is 125/disk. so you'll need 6 15krpm or 8 10krpm disks.