VM's on ESX Local Storage

[ianmellor]

Hi All,

This is an academic question. A bit of background, we are running 7 ESX 3.5 & VC 2.5 with 4 host's in a DRS & HA cluster with 2 MSA 1000 SAN's. We are using VCB. We have a consultant saying that we should use our ESX local storage to host our VM's. Besides the not being able to use DRS, HA and VCB what are the down sides to having your VM's on the ESX local storage?

Thanks,

[MR-T]

I can't see why a consultant would suggest local storage ahead of shared storage as you lose so much functionality.

If your MSA is running really slowly, you might get quicker disk access on local drives, but that's the only advantage I can think of.

If you must use the local storage, you can place the virtual machine swap files on here now with ESX 3.5. This could give you back a few GB on the MSA1000's

[acr]

VMware VMFS File System is designed for concurrent write access from all hosts, this coudnt happen if you placed the VM's on Local Storage, as you are running VI3.5 you would also loose Storage VMotion as each ESX Host cannot see the other's local disk..

As you have it, the SAN is where your VM's belong..

[jrenton]

The only advantage of having local storage is really the cost. Have you run out of storage on your MSA1000s?

I cannot see why you would want to disable DRS and HA on your cluster. I do not understand your consultant's reasoning..

[ianmellor]

Hi,

He is saying that the esx host raid card and disks are faster than the SAN.

Thanks for your help.

[acr]

Whether the local disks were faster or not you loosing an awful lot more than you gain by placing the VMs on local storage.. For a very small and initail deployment or when budgets are very tight, purhaps worth a consideration..

[EMcCloud]

So fast you'd want to give up VM mobility (DRS, HA, Vmotion)? So fast you'd want to take downtime as each ESX server needs to be patched/updated? Not likely. We don't know your specific issues with the environment nor your goals. But from a planning strategy, I can't see a reason to go local over SAN unless you were really cash strapped. You are sacrificing the majority of the justifications to virtualize.