I have been following this issue some, and I think this could be a cause for silent corruption on RAID5 and RAID6. I don't think this has been mentioned, if so, sorry. If data blocks can be changed in memory before written to disk, even if the data blocks that were changed were never needed again from the disk, the other related blocks in the stripe are at risk. If the parity blocks are computed, then the 1 data block in memory is changed, then the blocks are written to disk, the parity would be wrong. If a disk fails and is re-added or replaced, the data block in that stripe will be computed using the changed block giving a now corrupt value. I am assuming the stripe has some data blocks that have needed data and at least 1 that was not needed, and that block that was not needed was changed before writing it to disk. And the disk that failed did not have the block that had been changed. I have a hard time conveying my thought in text. I hope you understand me. Thanks for reading. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
