Thursday, April 23, 2015

Disk.SchedQuantum (maximum number of consecutive “sequential” I/O’s per VM) one liner for Esxi

Another not so hard to remember one liner for my use when i need it.
what is Disk.SchedQuantum?
The maximum number of consecutive “sequential” I/O’s allowed from one VM before we force a switch to another VM (unless this is the only VM on the LUN). Disk.SchedQuantum is set to a default value of 8.
But how do we figure out if the next I/O is sequential or not? That's a good question.

get-vmhost | set-advancedconfiguration -name Disk.SchedQuantum -value "64"

The above will set the disk.schedquantum on all the hosts of the vcenter.