stop Disk Command - Performance

[tdubb123]

Under chart options, I do not see the stop disk command as a measurement

I see

Disk Commands Issues

Disk commands LAtency

[tdubb123]

The Avg time on

plysical read latency and physical write latency is > 20ms on many of my luns. Does this mean the storage is slow or having problems?

[jfelinski]

Hi,

Unfortunatelly there is no easy answer to you question, generally it always "depends". Your disks in the storage pool might be simply too slow, or number of spindles is not sufficient for current usage. Start with checking number of average/maximum IOPS on all LUN's, to do so simply go to

performance statistics -> disk -> number of commands issues and divide this by 20 to get IOPS.

Also tell us more about your storage, how many disks you have, what sort of RAID level you've used. Another helpfull thing will be do discover VM's hammering your storage and determine reads/writes ratio for hosted machines.

Regards!

---

MCSA+S, VCP 3, VCP 4

[PeterCr]

The Performance Troubleshooting Guide has been updated and reworded, the counter you want to look at now is 'Disk Command Aborts'

Check for command aborts

a. Select the host, then the Performance tab, then Advanced, then Switch to: Disk

b. Look at the measurement Command Aborts for all Datastore objects.