HP MR Gen10 Plus, User Manual, Page: 82 / 179

Write policy Write policy
The write policy options for the logical drive are:
Write Through (SSD only) - In this mode, the controller sends a data transfer completion signal to the host when the drive
subsystem has received all the data in a transaction. This mode may result in slower performance as it does not use the controller
cache.
Write Back - In this mode, the controller sends a data transfer completion signal to the host when the controller cache has received
all the data in a transaction. This option provides a good balance between data protection and performance as the controller
switches between write back and write through depending on the controller status.
Always Write Back - In this mode, the controller sends a data transfer completion signal to the host when the controller cache
receives all the data in a transaction. If you select the Always Write Back policy and the energy pack is absent, the firmware is
forced to use the Write Back policy.
This controller now supports two power options to enable the controller cache features. Collectively, these two options are known as
the "energy pack" and include the following:
HPE Smart Storage Battery
HPE Smart Storage Hybrid Capacitor
Since the interface does not display the cache policy used during the creation of the logical drive, you can identify the policy by:
Viewing the energy pack charge status in iLO and the write cache status.
Viewing cache policy information in the event log.
Temporarily disabling the cache, which displays the original cache setting.
Write policy 82