For the sake of knowledge. As both drive were in "good condition" according to ddrescue at least I simply have mount the new one in read only and got the data back to life mount -t ext4 -o ro /dev/sdb /mnt/data_disk/ /r Il giorno gio 6 feb 2025 alle ore 06:41 Raffaele Morelli <raffaele.morelli@xxxxxxxxx> ha scritto: > > Il giorno mer 5 feb 2025 alle ore 21:42 Pascal Hambourg > <pascal@xxxxxxxxxxxxxxx> ha scritto: > > > > On 05/02/2025 at 13:03, Raffaele Morelli wrote: > > > > > > Last week we found it was in read only mode, I've stopped and tried to > > > reassemble it with no success. > > > dmesg recorded this error > > > > > > [7013959.352607] buffer_io_error: 7 callbacks suppressed > > > [7013959.352612] Buffer I/O error on dev md126, logical block > > > 927915504, async page read > > > [7013959.352945] EXT4-fs (md126): unable to read superblock > > > > No error messages from the underlying drives ? > > I have logs to scan for details > > > > We've found one of the drive with various damaged sectors so we > > > removed both and created two images first ( using ddrescue -d -M -r 10 > > > ). > > > > Is either image complete or do both have missing blocks ? > > There are no errors, pct rescued is 100%, everything seems fine. > > > > We've set up two loopback devices (using losetup --partscan --find > > > --show) and would like to recover as much as possible. > > > > > > Should I try to reassemble the raid with something like > > > mdadm --assemble --verbose /dev/md0 --level=1 --raid-devices=2 > > > /dev/loop18 /dev/loop19 > > > > If the RAID members were partitions you must use the partitions > > /dev/loopXpY, not the whole loop devices. > > > > If either ddrescue image is complete, you can assemble the array in > > degraded mode from a single complete image. > > If both images are incomplete and the array has a valid bad block list, > > you can try to assemble the array from both images. > > > > In either case, assemble the array read-only. > > Actually we're here > > /dev/md0: > Version : 1.2 > Creation Time : Wed Feb 5 11:12:32 2025 > Raid Level : raid1 > Array Size : 3906885440 (3.64 TiB 4.00 TB) > Used Dev Size : 3906885440 (3.64 TiB 4.00 TB) > Raid Devices : 2 > Total Devices : 2 > Persistence : Superblock is persistent > > Intent Bitmap : Internal > > Update Time : Wed Feb 5 22:27:49 2025 > State : clean > Active Devices : 2 > Working Devices : 2 > Failed Devices : 0 > Spare Devices : 0 > > Consistency Policy : bitmap > > Name : aria-pcpl:0 (local to host aria-pcpl) > UUID : 3b27a574:b12fa078:28872721:15bf710c > Events : 7984 > > Number Major Minor RaidDevice State > 0 7 22 0 active sync /dev/loop22 > 1 7 23 1 active sync /dev/loop23
