I have an Ubuntu 14.04 server with btrfs (SSD drive) as /, and I have a bind of another drive (SATA) to /home. The SSD drive has reported that is out of free space, so I read this, applied some of the suggestions, and removed some files. This is what btrfs now reports:
# btrfs fi show /
Label: system uuid: 2322b989-2110-494b-96b0-40aaee2f3998
Total devices 1 FS bytes used 6.20GiB
devid 1 size 26.08GiB used 22.52GiB path /dev/sdc1
# btrfs fi df /
Data, single: total=21.76GiB, used=5.69GiB
System, single: total=4.00MiB, used=16.00KiB
Metadata, single: total=776.00MiB, used=522.03MiB
# btrfs subvolume list /
ID 257 gen 2090434 top level 5 path @
ID 258 gen 1048023 top level 5 path @home
df -h
/dev/sdc1 27G 6.3G 20G 25% /
It is safe to remove @home as it is actually a bind to another drive? But before that, I just want to be sure I'm reading the above numbers correctly... The drive is using around 6GB out of 26G, right?
UPDATE
This is my fstab (relevant parts):
UUID=2322b989-2110-494b-96b0-40aaee2f3998 / btrfs noatime,nodiratime,notreelog,ssd,discard,subvol=@ 0 1
UUID=858a4a9d-a901-47c7-89d2-0ef97ef6f23f /mnt/ext ext4 defaults,acl,user_xattr,noatime,nodiratime 0 1
/mnt/ext/home /home none bind
It looks like you can safely remove the
@home
subvolume. It is not mounted anywhere on boot.I recommend to check if there is anything important there left. You can unmount the HDD for that and see what is in
/home
.