On 06/06/2016 10:41 AM, Marc MERLIN wrote: > Howdy, I have a raid 5 where one drive reported this: > 197 Current_Pending_Sector 0x0032 200 199 000 Old_age Always - 29 > > So I did this: > myth:~# echo check > /sys/block/md5/md/sync_action > [173947.749761] md: data-check of RAID array md5 > (...) > [370316.769230] md: md5: data-check done. > > My understanding was that it was supposed to read every block of every > drive, and if some blocks were unreadable, use parity to rewrite them on > some fresh backup blocks. > If a block returned garbage instead, md5 cannot fix this not knowing which > block is wrong, but I'm assuming the check would have failed with an error. https://www.kernel.org/doc/Documentation/md.txt shows for sync_action check - A full check of redundancy was requested and is happening. This reads all blocks and checks them. A repair may also happen for some raid levels. repair - A full check and repair is happening. This is similar to 'resync', but was requested by the user, and the write-intent bitmap is NOT used to optimise the process. I think you wanted 'repair' not 'check'. --Sarah -- 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
