FATA disks in RAID5 for VMware guests

[daugavpils]

Hi All,

We are moving to the dataceneter and planning to have SQL servers (virtualized) and some Windows/Linux mixed environment .

We are considering tiered storage

on EVA4400 - FC RAID 10 for SQL databases and RAID5 across 24 FATA 1TB disks

for VMware ESX guests.guests will not be IO intensive, in total we will have about 40 vmguests.

HP is describing FATA disks as suitable for near online

storage, however I am not convinced that 24 spindles will not be enough for

running VMWare for our setup.

Does anyone has opinion on why this could

be a such a bad idea?

Thank you

Sergei

[msemon1]

More spindles = Better performance. I think your instinct is probably right.

Mike

[mcowger]

Assuming your guests do 100IOPs sustained each (not unreasonable, but having info from you would be good), thats 4000 IOPs you need to be able to sustain. 24 ATA disks (7200RPM) will do about 1800-2000 IOPs. Not enough :smileyshocked:

Again, this all assumes alot about your workoad.

--Matt

VCP, vExpert, Unix Geek

[AntonVZhbankov]

It depends on your VM IO load. Maybe it would be enough, maybe not.

As already said 24 FATA disks = about 2000 IOPS.

---

MCSA, MCTS, VCP, VMware vExpert '2009

http://blog.vadmin.ru

[daugavpils]

Thank you all,

Currently our VI is connected to CX3-10 EMC array and most logical way to measure IOPs would be to get stats from this array.Unfortunately enabling stats requires additional licensing.I believe my only choice here is running perfmon for windows and something similiar for linux, then aggregate the data.

Sergei

[J1mbo]

If 12TB is sufficeint then the ATA disks should perform quite a bit better in Raid-10, particularly in writes because of the high latency for raid-5 with 7.2k disks.

Please award points to any useful answer.