On Sun, 23 Nov 2008, Brad Campbell wrote: > md has done this for a while now though. If it encounters a read error in > the array it will make an attempt to write the reconstructed data back to > that disk attempting to force a reallocation. I've seen it work quite > well here on disks that have the occasional grown defect. Indeed, but it does so in the "check array" mode (which distros like Debian are now enabling once-a-month or so, I always up that to once a week :p) Does md repair bitrotten sectors ALSO outside of check mode? That's what is being asked in this thread... > If the disk is haemorrhaging sectors then you will find out about it > sooner or later through other means. Like a weekly SMART long test. That's what our maintenance windows are for :) Everything is kept on-line, but allowed to run in degraded performance mode, so we kick in SMART offline and long tests, RAID array scrubbing, etc (not at the same time, though!). That reminds me to file a bug against smartmontools to DISABLE auto offline mode on disks, and enable them one disk at a time at a random interval with at least one hour between them. Otherwise, the disks all enter auto-offline-testing SMART mode at the same time. Hmm, it would be good to teach md to measure disk throughput using a sliding window (of say, 5 minutes) and reduce read priority of disks that are slow... -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- 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
