With the release of VMware View 5.1 a number of new features have been introduced, particularly around storage performance. For me, the key feature is the View Storage Accelerator, or you may hear it referred to as Host Caching.
Without going into intricate detail, the storage accelerator basically creates an additional file within the datastores for the replica disk and all linked clone OS disk. This file is know as a digest file and is used as a caching mechanism. The way this digest file increases performance is by minimising the amount of read requests back to the replica disk. This is done by caching commonly read blocks from the replica disk into the OS disk digest file which can be read directly acting as a cache. This can help minimise boot and log on storms within your View environment.
Enabling the Storage Accelerator is relatively simple and can be achieved by following the below steps.
Step 1. Log in to you VMware View administrator console, under View Configuration click servers. Locate your vCenter server and click Edit.
Step 2. Click on the Host Caching tab then check the Enable host caching for view check box. This will enable the caching capability and allow you to specify the size of the cache for all, or individual hosts. The minimum cache size is 100MB with a maximum of 2GB. Click OK to apply the change.
Step 3. Locate a linked clone pool you want to enable the storage accelerator on and Edit the settings. Click on the far right tab named Advanced Storage and check the Use host caching check box. Click OK to apply the settings.
The storage accelerator features is now enabled for this linked clone pool, and will require a recompose to generate the necessary digest files. Hopefully you will now see a performance increase on read intensive operations.
Thanks for reading.