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RAID settings / performance tuning

Posted: Mon Aug 12, 2013 3:01 pm
by bgarlock
Hi,

I've had the free version of the iSCSI SAN in our lab, and testing things out using the virtual disk image option. I'll usually create a virtual disk image iSCSI target, then format the iSCSI target as VMFS5, and run some VM guests off of it. I'm getting ready to consider purchasing the pay version, and possibly get into the HA options. I'm wondering a couple of things about JBOD array I will be using for this, and here's the specs:

* It's an HP MSA-60, with 12, 300GB 15k SAS drives
* RAID-6
* Gives me 2.8TB usable

What would be a good 'strip size' to choose, and what would be the best way to setup the Starwind side of things? Should I stick with virtual disk images or what would get me the best performance and reliability?

Many thanks,

Bruce

Re: RAID settings / performance tuning

Posted: Tue Aug 13, 2013 9:33 am
by anton (staff)
Generally speaking parity RAIDs are far from the best choice for VM storage from the performance point of view.

VM workload has a lot of a small writes so you'd better keep stripe size as small as possible.

Good news: V8 will have LSFS so parity RAIDs will strike back with a RAID0-like performance for writes :)
bgarlock wrote:Hi,

I've had the free version of the iSCSI SAN in our lab, and testing things out using the virtual disk image option. I'll usually create a virtual disk image iSCSI target, then format the iSCSI target as VMFS5, and run some VM guests off of it. I'm getting ready to consider purchasing the pay version, and possibly get into the HA options. I'm wondering a couple of things about JBOD array I will be using for this, and here's the specs:

* It's an HP MSA-60, with 12, 300GB 15k SAS drives
* RAID-6
* Gives me 2.8TB usable

What would be a good 'strip size' to choose, and what would be the best way to setup the Starwind side of things? Should I stick with virtual disk images or what would get me the best performance and reliability?

Many thanks,

Bruce