Increase number of VMotions per host

Generally I don’t link to other virtualization blogs without any form of expansion on their articles by myself, but for this gem, I’ll make an exception:

Fine tuning concurrent VMotions allowed by vCenter

And the relevant stuff from the above article:

Here are the steps to increase the amount of Simultaneous VMotion Migrations per Host.

1. RDP to your vCenter Server.
2. Locate the vpdx.cfg (Default location “C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter”)
3. Make a Backup of the vpdx.cfg before making any changes
4. Edit the file in using WordPad and insert the following lines between the <vpdx></vpdx> tags;

<ResourceManager>
<maxCostPerHost>12</maxCostPerHost>
</ResourceManager>

5. Now you need to decide what value to give “maxCostPerHost”.

A Cold Migration has a cost of 1 and a Hot Migration aka VMotion has a cost of 4. I first set mine to 12 as I wanted to see if it would now allow 3 VMotions at once, I now permanently have mine set to 24 which gives me 6 simultaneous VMotions per Host (6×4 = 24).

I am unsure on the maximum value that you can use here, the largest I tested was 24.

6. Save your changes and exit WordPad.
7. Restart “VMware VirtualCenter Server” Service to apply the changes.

Remember, this is per host so two ESX servers with a setting of “12″ in VirtualCenter would be able to do 6 VMotions concurrently between them.

Cheers,

Leo