Integrated Dell Remote Access Controller 9 User's Guide

The Managed Preserved Cache feature is a controller option which provides the user an option to discard the controller cache data. In the write-back policy, data is written to the cache before being written to the physical disk. If the virtual disk goes offline or is deleted for any reason, the data in the cache gets deleted.

The PREC Controller preserves the data written on the preserved or dirty cache in an event of power failure or cable disconnect until you recover the virtual disk or clear the cache.