Marc MERLIN
2014-Mar-23 15:25 UTC
btrfs-tools missing "btrfs device delete devid=x path" ?
I'm still doing some testing so that I can write some howto.
I got that far after a rebalance (mmmh, that took 2 days with little
data, and unfortunately 5 deadlocks and reboots.
polgara:/mnt/btrfs_backupcopy# btrfs fi show
Label: backupcopy uuid: eed9b55c-1d5a-40bf-a032-1be6980648e1
Total devices 11 FS bytes used 114.35GiB
devid 1 size 465.76GiB used 32.14GiB path /dev/dm-0
devid 2 size 465.76GiB used 32.14GiB path /dev/mapper/crypt_sdd1
devid 3 size 465.75GiB used 0.00 path <---- drive is freed up
now.
devid 4 size 465.76GiB used 32.14GiB path /dev/dm-2
devid 5 size 465.76GiB used 32.14GiB path /dev/dm-3
devid 6 size 465.76GiB used 32.14GiB path /dev/dm-4
devid 7 size 465.76GiB used 32.14GiB path /dev/mapper/crypt_sdi1
devid 8 size 465.76GiB used 32.14GiB path /dev/dm-6
devid 9 size 465.76GiB used 32.14GiB path /dev/mapper/crypt_sdk1
devid 10 size 465.76GiB used 32.14GiB path /dev/mapper/crypt_sdl1
devid 11 size 465.76GiB used 32.14GiB path /dev/mapper/crypt_sde1
Btrfs v3.12
What's the syntax for removing a drive that isn't there?
I'm looking for something like
polgara:/mnt/btrfs_backupcopy# btrfs device delete devid=3 .
ERROR: error removing the device 'devid=3' - No such file or directory
Until I can remove it, not surprisingly, even though device 3 is now
unused, I still need to mount degraded:
polgara:~# mount -v -t btrfs -o compress=zlib,space_cache,noatime
LABEL=backupcopy /mnt/btrfs_backupcopy
mount: wrong fs type, bad option, bad superblock on /dev/mapper/crypt_sde1,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
[28865.527656] BTRFS: open devid=3 failed
[29777.507022] BTRFS: device label backupcopy devid 11 transid 5137
/dev/mapper/crypt_sde1
[29777.558874] BTRFS info (device dm-9): disk space caching is enabled
[29777.566997] BTRFS: failed to read chunk tree on dm-9
[29777.612041] BTRFS: open_ctree failed
polgara:~# mount -v -t btrfs -o compress=zlib,space_cache,noatime,degraded
LABEL=backupcopy /mnt/btrfs_backupcopy
/dev/mapper/crypt_sde1 on /mnt/btrfs_backupcopy type btrfs
(rw,noatime,compress=zlib,space_cache,degraded)
polgara:~#
This works.
I think if I get that last step working, I will have succcessfully removed a
raid5
drive, added a new drive, rebalanced existing data on it, and removed the old
one.
Thanks,
Marc
--
"A mouse is a device used to point at the xterm you want to type in" -
A.S.R.
Microsoft is to operating systems ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/ | PGP 1024R/763BE901
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