Hello Anand, the failed disk was removed. My procedure was the following: - I found some write errors in the kernel log, so - I shutdown the system - I removed the failed disk - I powered on the system - I mounted the remaining disk degraded,rw (works OK) - the system works an and was rebooted some times, mounting degraded,rw works - suddentlym mounting degraded,rw stops working and only degraded,ro works. Thanks, Martin Am Mittwoch, 10. Juni 2015, 15:46:52 schrieb Anand Jain: > On 06/10/2015 02:58 PM, Martin wrote: > > 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. > > the failed(ing) disk is it still physically in the system ? > when btrfs finds EIO on the intermittently failing disk, > ro-mode kicks in, (there are some opportunity for fixes which > I am trying). To recover, the approach is to make the failing > disk a missing disk instead, by pulling out the failing disk > from the system and boot. When system finds disk missing > (not EIO rather) it should mount rw,degraded (from the VM part > at least) and then replace (with a new disk) should work. > > Thanks, Anand > > > "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 > > -- > 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
