Just a reminder: Don't just count the drives. Imagine the setup. If you configure the controllers symmetrically they should both have a spare and RAID-DP, leaving you with just _3 data spindles_ per controller if you go for the 12-disk offer. If you configure asymmetrically you'll get something like:
* 1+1 (RAID 4 root vol) * 1 Spare, _7 Data_ + 2 Parity
So 7 Data spindles, but only one active controller (the other one being idle most of the time, I presume). 7*~250 IOPS = 1.700 IOPS at the spindles... (The controller shouldn't be the bottleneck...)
I still have an uneasy feeling here...
In conclusion: If you can't afford the 24-disk offer, consider at least an asymmetric configuration!
Sebastian
On 23.10.2012 16:16, Milazzo Giacomo wrote:
Hi all,
I've a startup project that will expect a very simple Hyper-V 2012 iSCSI cluster. Competitor is an EqualLogic appliance 24x300 10k SAS HDs.
There's a very interesting promo in these days offering a 2220 12x900 SAS at very competitive price vs a 2240-2 24x450 SAS so I was evaluating the 2220.
But I'm concerned about performances. The two server nodes will be "only" 32 GB RAM/2 CPU Xeon 8C so I can presume that the number of VM servers will be no more that 7-8
I've lab data from NetApp that state, at lab conditions, that for short random ops with iSCSI the 2220 can do roughy 10k IOPS vs the 30k of the 2240-2, for short write they are quite similar (40k IOPS).
For large ops the 2240-2's performances are very higher that 2220.
In addition to this I've also considered that the 2220 will have ONLY 6 mechanics for each controller while the 2240 will have 12 each...
What do you think about this little cluster? Can I trust in 2220?
Regards
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