Thanks Phil, I wrote "mdadm -E /dev/sd[abcde]" instead of "mdadm -E /dev/sd[abcde]1"... Anyway, I'm currently trying your advice with dd_rescue, I'll report back when something happens. Nicholas Ipsen On 9 January 2013 23:33, Tudor Holton <tudor@xxxxxxxxxxxxxxxxx> wrote: > Having been through this process recently, and I agree that the advice will > most likely lead the user to speculate on this as a potential cause, is > there some way we could more easily alert the user to this situation? Maybe > we could mark the disk with a (URE) tag in mdstat (my preference) and/or > reporting the error as "md: URE error occurred during read on disk X, > aborting synchronization, returning discs [Y,Z...] to spare"? Trailing logs > during synchronization can take several hours on large arrays (and busy > servers) and cause alot of time wastage, particularly if you don't know what > you're looking for. > > Since it first affected me I found this kind of question asked quite > regularly on a multitude of tech forums and alot of the responses I came > across were incorrect or misleading at best. Alot more were along the lines > of "That happened to me, and after trying to fix it for days I just wiped > the array and started again. Then it happened to the array again later. > mdadm is so unstable!" Unfortunately we can't avoid people blaming the > software, but we can at least help them to diagnose the problem more quicky > and help their pain and our reputation. :-) > > Incidentally, is the state "active faulty" an allowed state? Because that > could be a good way to report it, also. > > On 10/01/13 08:18, Nicholas Ipsen(Sephiroth_VII) wrote: >> >> --snip--- >> >> >> On 9 January 2013 18:55, Phil Turmel <philip@xxxxxxxxxx> wrote: >>> >>> On 01/09/2013 12:21 PM, Nicholas Ipsen(Sephiroth_VII) wrote: >>>> >>>> I recently had mdadm mark a disk in my RAID5-array as faulty. As it >>>> was within warranty, I returned it to the manufacturer, and have now >>>> installed a new drive. However, when I try to add it, recovery fails >>>> about halfway through, with the newly added drive being marked as a >>>> spare, and one of my other drives marked as faulty! >>>> >>>> I seem to have full access to my data when assembling the array >>>> without the new disk using --force, and e2fsck reports no problems >>>> with the filesystem. >>>> >>>> What is happening here? >>> >>> You haven't offered a great deal of information here, so I'll speculate: >>> an unused sector one of your original drives has become unreadable (per >>> most drive specs, occurs naturally about every 12TB read). Since >>> rebuilding an array involves computing parity for every stripe, the >>> unused sector is read and triggers the unrecoverable read error (URE). >>> Since the rebuild is incomplete, mdadm has no way to generate this >>> sector from another source, and doesn't know it isn't used, so the drive >>> is kicked out of the array. You now have a double-degraded raid5, which >>> cannot continue operating. >>> > --snip-- > -- > 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 -- 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
