Creating a persistent scratch location for ESXi

You can configure persistent scratch space for ESXi using the vSphere Client:

1. Connect to vCenter Server or the ESXi host using the vSphere Client.
2. Select the ESXi host in the inventory.
3. Click the Configuration tab.
4. Click Storage.
5. Right-click a datastore and select Browse.
6. Create a directory for this ESX host (eg, locker-servername)
7. Close the Datastore Browser.
8. Click Advanced Settings under Software.
9. Select the ScratchConfig section.
10. Change the ScratchConfig.ConfiguredScratchLocation configuration option, specifying the full path to the directory.
    eg. /vmfs/volumes/DatastoreName/locker-servername
11. Click OK.
12. Put the ESXi host in maintenance mode and reboot for the configuration change to take effect.

You could also use vCLI or PowerCLI to make the change but I found the above procedure easier to use.