Arch Linux

3psus

Member

From: Quebec

Registered: 2015-08-09

Posts: 1

btrfs device delete - not enough space?

My btrfs raid5 recently became full. After running btrfs device delete to remove a 500GB device before adding a 3TB one (all sata ports are populated), the command exited on an error telling me there was no space left on device, thus cancelling the delete action. Now, given those numbers: (ignore the 0.00B used on /dev/sda, btrfs device delete is running again)

Label: 'Arch Linux btrsf'  uuid: 3c3d58fd-3f9b-4201-acea-27ebd1e4f2c9
        Total devices 5 FS bytes used 3.58TiB
        devid    1 size 445.76GiB used 445.76GiB path /dev/sdd3
        devid    2 size 2.73TiB used 2.39TiB path /dev/sde
        devid    3 size 0.00B used 303.91GiB path /dev/sda
        devid    4 size 465.76GiB used 465.76GiB path /dev/sdc
        devid    5 size 2.73TiB used 2.73TiB path /dev/sdb

and

WARNING: RAID56 detected, not implemented
WARNING: RAID56 detected, not implemented
WARNING: RAID56 detected, not implemented
Overall:
    Device size:                   6.35TiB
    Device allocated:                0.00B
    Device unallocated:            6.35TiB
    Device missing:                  0.00B
    Used:                            0.00B
    Free (estimated):                0.00B      (min: 8.00EiB)
    Data ratio:                       0.00
    Metadata ratio:                   0.00
    Global reserve:              512.00MiB      (used: 4.22MiB)

Data,RAID5: Size:3.57TiB, Used:3.57TiB
   /dev/sda      303.56GiB
   /dev/sdb        2.72TiB
   /dev/sdc      465.76GiB
   /dev/sdd3     444.42GiB
   /dev/sde        2.39TiB

Metadata,RAID5: Size:8.03GiB, Used:6.67GiB
   /dev/sda      352.00MiB
   /dev/sdb        6.34GiB
   /dev/sdd3       1.34GiB
   /dev/sde        6.34GiB

System,RAID5: Size:32.00MiB, Used:656.00KiB
   /dev/sdb       32.00MiB
   /dev/sde       32.00MiB

Unallocated:
   /dev/sda       16.00EiB
   /dev/sdb        1.02MiB
   /dev/sdc        1.02MiB
   /dev/sdd3       1.00MiB
   /dev/sde      342.38GiB

shouldn't the system have enough space to remove the device (/dev/sda)? I see that /dev/sde has 342GB unallocated and /dev/sda needs 303GB of free space to get removed (if my understanding is correct). If not, given that devices are identified with UUID in fstab, can I just plug the new device through esata, run btrfs device replace /dev/sda /dev/sd(esata) and then install my newly balanced HDD in place of /dev/sda?