vSAN sparse swap files

With vSAN 6.2 you can save a lot of capacity if you use the new feature called „sparse VM swap object“. It will deploy the swap file of every VM stored in vSAN as sparse. So you are able to safe nearly all of your VMs RAM inside the vSAN datastore.

Setup:

1. Use SSH/Putty to connect direct to the ESX and login as root.
2. esxcfg-advcfg -s 1 /VSAN/SwapThickProvisionDisabled
3. After the command the SwapThickProvisionDisabled value should be set to 1.
4. Check with esxcfg-advcfg -g /VSAN/SwapThickProvisionDisabled
5. Repeat step 2 for all hosts in the vSAN cluster and the witness host.

Now every VM that will be started in this vSAN gets a thin provisioned vswp file. You can do this also if the cluster is live, but you need to shutdown and reboot every single VM after set the sparse command till the effect takes place.