Chris Murphy <li...@colorremedies.com> writes: > On Apr 18, 2014, at 8:36 PM, Michael Welsh Duggan <m...@md5i.com> wrote: > >> I had a disk in my RAID0 die: >> >> root@maru2:~# /usr/local/src/btrfs-progs/btrfs fi show >> 8c530f6f-7592-4d57-854d-1fae33ae7cb6 >> Label: none uuid: 8c530f6f-7592-4d57-854d-1fae33ae7cb6 >> Total devices 3 FS bytes used 329.66GiB >> devid 1 size 1.79TiB used 357.03GiB path /dev/sdd1 >> devid 3 size 931.51GiB used 178.00GiB path /dev/sdf >> *** Some devices missing >> >> Btrfs v3.12-43-gc2081e2-dirty >> >> So, I try to mount it with -o degraded. That fails, implying that a >> degraded mount needs to be read-only. So I successfully mount it read >> only. Then I want to add a new disk to replace the missing one: >> >> root@maru2:~# /usr/local/src/btrfs-progs/btrfs dev add /dev/sdg /mnt/ >> ERROR: error adding the device '/dev/sdg' - Read-only file system >> >> So I can't add a disk if it's mounted read-only, and can't mount it >> read-write? What am I missing? What's my way around this? > > Not really because it's raid0. The minimum number of disks for a 3 > disk raid0 is 3 disks. Upon losing one, the data portion of the file > system is toast. I'm guessing it lets you mount it ro,degraded because > the metadata and hence the file system itself, is raid1 (the default > for raid0 data volumes). > > The file system could determine what files aren't damaged, i.e they > exist entirely on one of the remaining two drives, with no dependency > on the dead one. But I don't think this code exists yet. You could > possibly rsync the drive to another file system, and bad files damaged > by the missing disk will be reported in dmesg while the good ones > would still copy over. I haven't tried this.
My mistake. I meant RAID1. -- Michael Welsh Duggan (m...@md5i.com) -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
