Supermicro X11QPL User Manual page 174

Super X11QPL User's Manual
RWH Policy
Press <Enter> and the following screen will appear. If any device has been set as a journaling
drive (see pages 171 and 172), the options are Distributed PPL, Journaling Drive, and
Disable.
If no device has been set as a journaling drive, the options are Distributed PPL and Disable.
Note 1: Partial parity logging (PPL) can be defined as the result of XOR calculation of
old data and old parity. PPL is a feature available for RAID5 volumes. While a power/
drive-failure/crash occurring, PPL information helps rebuild the RAID volume and re-
duce the potential data loss.
Note 2: For the RWH condition, the Intel® RSTe 5.X or above RWH closure algorithm
provides the option of use of an additional NVMe device for RAID volume rebuilds
(Journaling Drive RWH closure mode). Without the use of an additional NVMe device,
PPL distributed RWH closure mode can be utilized to close the RWH by using the
parity drive for example.
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