hesela.devPartial Parity Log
Partial Parity Log is a Linux MD RAID5 mechanism that records the XOR of untouched stripe chunks before dispatching data and parity updates.
The log resides on the stripe's parity member. Its recovery scope is narrower than a data journal.
Relations
- related
- raid-write-hole, raid-5, parity-raid, write-intent-bitmap
Advantages
- No separate journal device is required. [1]
Limitations
- Does not guarantee preservation of in-flight data; loss of a modified member is outside that protection. [1]
- The documented Linux MD implementation does not combine PPL with a write-intent bitmap. [1]