On 10.06.2013 14:44, Bart Van Assche wrote: > On 06/10/13 14:05, Sebastian Riemer wrote: >> Perhaps, I should collect all guys who require MD RAID-1 for remote >> storage replication in order to put some pressure on Neil. > > If I remember correctly one of the things Neil is trying to explain to > md users is that when md is used without write-intent bitmap there is a > risk of triggering a so-called write hole after a power failure ?
I'm not sure. Haven't seen something like this on the mailing list. Do you have a reference from the archives? I think this is handled by superblock writes in the correct order by now. The main reason for the write-intent bitmap remains from my knowledge that you need a full resync without it if a component device is down for a short moment in time. It becomes faulty. If you know that there can't be a hardware issue (e.g. virtual storage), you can remove the faulty device and re-add it to the array. If a device was faulty, then it assembles again. There is an error counter in /sys/block/mdX/md/ sysfs and a maximum read error count (usually 20) after which the faulty device doesn't assemble again. /sys/block/mdX/md/dev-Y/errors /sys/block/mdX/md/max_read_errors Cheers, Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
