About SAN policies
Citrix Provisioning clients always failover to server side cache during boot when the vDisk mode is set to Cache in device RAM with overflow on hard disk.
An option has been removed from the Cache type field in the vDisk Properties window. The option Cache on device hard disk is no longer available from the list because it does not support ASLR. The replacement for this field is Cache in device RAM with overflow on hard disk. For more information, see Features removed from future releases.
Resolving failover to server side caching during boot
In a provisioning target device booting in private vDisk mode or maintenance vDisk version, open a command prompt with administrator privileges.
Run the DiskPart utility, using the following command:
To verify the SAN policy, run the command:
Diskpart > san
The SAN policy is configured as Online All for PVS target devices. Ths configuration allows it to function correctly while in Cache in Device RAM with Overflow on Hard Disk mode.
To change the SAN policy, run the command:
Diskpart > san policy=OnlineAll
Shut down the target device and change the vDisk mode to standard image or promote the maintenance version to test or production version.
The SAN policy causes the write cache drive to remain offline. During boot, the target device determines that the write cache drive is ineligible for use as a write cache. As a result, it fails over to server side cache.
When creating a machine template, ensure that it has a similar hard disk drive structure. The machine template must boot from a vDisk in private image mode. For example:
- To PXE boot a VM with write cache, create a VM with 1 hard disk drive.
- To use Boot Device Manager (BDM) to boot a VM with write cache, create a VM with 2 hard disk drives.