Monday, 22 July 2013

oVirt Testing - English instructions for raising swap threshold

oVirt 3.2 Small Test System Admin Notes

I'm testing oVirt in the office to get a few things straight - I'm going to try and keep track of my experiences here.

For comparison, I'm running oVirt 3.2 on Fedora 18.

Can't start VM - Host swap percentage error

My first problem (I'm using a fairly constrained single-host setup initially) is that I am very short of memory on my test host.  oVirt refuses to start VMs when swap usage is over a threshold.  I couldn't find anywhere in the management pages to set this threshold, and a good bit of googling returned mainly development threads on the subject of memory and swap handling in larger environments.

Below I have shown the solution to the error message I received:
Cannot run VM. Host swap percentage is above the defined threshold. – Check your configuration parameters for Host Swap Percentage.
 To increase the defined threshold (or just check the current value), here are the commands:

* Check the current value:
[root@ov01 ~]# engine-config -g BlockMigrationOnSwapUsagePercentage
* Expected output:
BlockMigrationOnSwapUsagePercentage: 0 version: general
 * Set the value (to 75% usage in this example):
engine-config -s BlockMigrationOnSwapUsagePercentage=75 -cver=general

* Re-start the engine service:
systemctl restart ovirt-engine.service

Hope this helps someone, I'm sure I'll come back to it again if I build out any more small test systems


Виталий Исаев said...

Thank you, it was very usefull.

Anant Techtree said...

Thanks buddy. help me a lot