Hello Anand, the > mount -o degraded <good-disk> <-- this should work is my problem. The fist times it works but suddently, after a reboot, it fails with message "BTRFS: too many missing devices, writeable mount is not allowed" in kernel log. "btrfs fi show /backup2" shows: Label: none uuid: 6d755db5-f8bb-494e-9bdc-cf524ff99512 Total devices 2 FS bytes used 3.50TiB devid 4 size 7.19TiB used 4.02TiB path /dev/sdb2 *** Some devices missing I suppose there is a "marker", telling the system only to mount in ro-mode? Due to the ro-mount I can't replace the missing one because all the btrfs- commands need rw-access ... Martin Am Mittwoch, 10. Juni 2015, 14:38:38 schrieb Anand Jain: > Ah thanks David. So its 2 disks RAID1. > > Martin, > > disk pool error handle is primitive as of now. readonly is the only > action it would take. rest of recovery action is manual. thats > unacceptable in a data center solutions. I don't recommend btrfs VM > productions yet. But we are working to get that to a complete VM. > > For now, for your pool recovery: pls try this. > > - After reboot. > - modunload and modload (so that kernel devlist is empty) > - mount -o degraded <good-disk> <-- this should work. > - btrfs fi show -m <-- Should show missing if you don't let me know. > - Do a replace of the missing disk without reading the source disk. > > Good luck. > > Thanks, Anand > > On 06/10/2015 11:58 AM, Duncan wrote: > > Anand Jain posted on Wed, 10 Jun 2015 09:19:37 +0800 as excerpted: > >> On 06/09/2015 01:10 AM, Martin wrote: > >>> Hello! > >>> > >>> I have a raid1-btrfs-system (Kernel 3.19.0-18-generic, Ubuntu Vivid > >>> Vervet, btrfs-tools 3.17-1.1). One disk failed some days ago. I could > >>> remount the remaining one with "-o degraded". After one day and some > >>> write-operations (with no errrors) I had to reboot the system. And now > >>> I can not mount "rw" anymore, only "-o degraded,ro" is possible. > >>> > >>> In the kernel log I found BTRFS: too many missing devices, writeable > >>> mount is not allowed. > >>> > >>> I read about https://bugzilla.kernel.org/show_bug.cgi?id=60594 but I > >>> did no conversion to a single drive. > >>> > >>> How can I mount the disk "rw" to remove the "missing" drive and add a > >>> new one? > >>> Because there are many snapshots of the filesystem, copying the system > >>> would be only the last alternative ;-) > >> > >> How many disks you had in the RAID1. How many are failed ? > > > > The answer is (a bit indirectly) in what you quoted. Repeating: > >>> One disk failed[.] I could remount the remaining one[.] > > > > So it was a two-device raid1, one failed device, one remaining, unfailed. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" 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-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
