vSphere 5 Datastore Recommended Threshold

[hafuzu]

Hi,

Currently i'm working on Datastore Perfomance Monitoring report. Is there any guide for me to refer for the best recomended threshold to monitor the I/O perfomance for the datastore?

Thank You,

Hafuzu

[UmeshAhuja]

Hi,

Best practice is to always have 20% free space.

For more refet to --> http://communities.vmware.com/thread/257031

[hafuzu]

Hi Umesh,

Thank You.Currently i'm working on the Datastore Perfomance Report. Except for the free space, any other factor to me to consider? What is the best recomended threshold to monitor the Datastore latency?

Thank You,

Hafuzu

[CHogan]

Well, we've used 30msec as the threshold for Storage I/O Control in previous versions of vSphere, so that's probably a good starting point.

However, this is very much dependent on the datastore (and what devices/configuration backs the datastore). For this reason, the SIOC latency threshold is automatically determined using device modeling in vSphere 5.1.

HTH

Cormac

[EdWilts]

An acceptable latency level is really dependent on what kinds of applications you're running, and sadly, what your users are used to and willing to tolerate.

For database-related datastores, you're probably aiming for 5-10ms.  For more general purpose stuff, short spikes of 20ms are usually acceptable.

VMware says that you should not exceed 10ms for an extended period of time (http://kb.vmware.com/kb/1008205).

If you exceed 50ms for an extended period of time, your host may crash (been there, done that).

[EdWilts]

I'll add Scott Lowe's recommendations (from his SolarWinds presentation (registration required) at http://www.solarwinds.com/resources/webcasts/virtual-storage-analysis-with-solarwinds-virtualization...

Device latency should be 0-5 ms for high-speed devices - 4/8Gbps FC and 10Gbps iSCSI/NFS

Device latency should be 5-10 ms for low-speed devices (e.g 7200 RPM SATA) - 1/2 Gbps FC and 1Gbps iSCSI/NFS