You can change the percentage of space allocated for host cache or disable the host's ability to swap to host cache.
Use this procedure if your ESXi host is version 5.1 or earlier, or if you do not have a virtual flash licence. To configure host cache on an ESXi 5.5 or later host that has a virtual flash licence, use the virtual flash resource. For information, see About VMware vSphere Flash Read Cache.
You must have an SSD-backed datastore in your inventory.
- Browse to the host in the vSphere Web Client navigator.
- Click the Manage tab.
- Under the Storage tab, click Host Cache Configuration.
- Select the datastore in the list and click the Allocate space for host cache icon.
- Select a size for the host cache allocation on the drive.
- To disable the ability for the host to swap to host cache on a per-datastore basis, deselect the Allocate space for host cache check box.
- Click OK.