2014-10-06 15:53 GMT+02:00 Robin Hill <robin@xxxxxxxxxxxxxxx>: > On Mon Oct 06, 2014 at 03:39:12PM +0200, Patrik Horník wrote: > >> 2014-10-06 15:36 GMT+02:00 Robin Hill <robin@xxxxxxxxxxxxxxx>: >> > On Mon Oct 06, 2014 at 03:29:13PM +0200, Patrik Horník wrote: >> > >> >> Hello, >> >> >> >> is it possible to cancel RAID 6 array check? echo check > >> >> /sys/block/mdX/md/sync_action apparently only pauses it and next check >> >> continuing from saved position. (I guess /sys/block/mdX/md/sync_min) >> >> >> >> I want to achieve two things: >> >> >> >> - Start check from the start of the array. >> >> >> >> - Be sure I can shutdown array without any ill effect because check >> >> was interrupted. >> >> >> >> I guess that position will be cleared when array is stopped and >> >> started again, but I dont want to guess and experiment... :) >> >> >> > >> > You'd echo idle to the sync_action to pause/stop the check. If you want >> > to restart from the beginning next time, just echo 0 to sync_min >> > (similarly, if you just want to check/repair a specific range then set >> > sync_min and sync_max before the check/repair). >> > >> OK, thanks. So that should be fully working and correct way to do it >> and I cant harm my array by this in any way? >> > A check is always safe (well, excepting physical disk issues or issues > with overloading the I/O subsystem, but those are issues not limited to > check) as it's read-only. > > The sync_min and sync_max values need to be multiples of the chunk size > (it throws an error otherwise), which ensures a whole stripe is being > checked/repaired (otherwise you could have issues). > > The kernel documentation describes setting sync_min/sync_max, so it's an > expected operation. Whether there's another way of doing the same thing > I don't know - I've not heard of one though. If that is recommended way in kernel documentation, that is of course all I wanted :) BTW sync_min is reset to 0 also when you stop and start the array as I found out... > > Cheers, > Robin > -- > ___ > ( ' } | Robin Hill <robin@xxxxxxxxxxxxxxx> | > / / ) | Little Jim says .... | > // !! | "He fallen in de water !!" | -- 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
