Hi Matthew and all, thank you for taking action immediately. I really appreciate your effort.
After investigating the issue further I have to add that the mount option discard seems to trigger the issue, too. @Trent The general problem here is that RAID10 can balance single read streams to all disks (which is probably the major advantage over RAID1 effectively providing you RAID0 read speed; RAID1 needs parallel reads to achieve this). That said it is no big surprise that several machines at our site went to readonly mode after *some time* (probably reading some filesystem relevant data from the "bad disk"). Unfortunately the "clean first disk" only happens if you act immediately, otherwise you might have some data corruption. I verified this on one system where the root partition was affected using the debsums tool (just run debsums -xa) after fixing FS errors. My procedure to recover was: Assembly of the RAID: mdadm --assemble /dev/md127 /dev/nvme0n1p2 mdadm --run /dev/md127 Filesystem check on all partitions (note the -f parameter, some FS "think" they are clean): fsck.ext4 -f /dev/VolGroup/... Re-add the second component: mdadm --zero-superblock /dev/nvme1n1p2 mdadm --add /dev/md127 /dev/nvme1n1p2 Best regards -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1907262 Title: raid10: discard leads to corrupted file system To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1907262/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs