Ubuntu – Mounting BTRFS, no space available

btrfsfilesystem

After a win10 upgrade gone wrong, my boot sequence is broken and now I can't write on my BTRFS partition.

Here's the content of my ssd

Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc4476e04

Device     Boot     Start       End   Sectors   Size Id Type
/dev/sda1            2048    206847    204800   100M  7 HPFS/NTFS/exFAT
/dev/sda2  *       206848 566209347 566002500 269.9G  7 HPFS/NTFS/exFAT
/dev/sda3       566210560 567169023    958464   468M 27 Hidden NTFS WinRE
/dev/sda4       567171072 976773167 409602096 195.3G  5 Extended
/dev/sda5       567173120 976773119 409600000 195.3G 83 Linux

sda5 is my BTRFS partition, it contains

@  @apt-snapshot-release-upgrade-wily-2015-11-20_20:54:08  @home  boot

DF is telling there is no space left on device

df
Filesystem     1K-blocks      Used Available Use% Mounted on
/dev/sda5      204800000 149884472         0 100% /
udev            12307620         0  12307620   0% /dev

df -i
Filesystem      Inodes IUsed   IFree IUse% Mounted on
/dev/sda5            0     0       0     - /
udev           3076905   777 3076128    1% /dev

However, 204800000 1K-blocks minus 149884472 used equal 54915528 KB free, Gparted and Palimpsest are also reporting more than 50GB free.

As explained here, I tried to rebalance the FS

sudo btrfs fi show
Label: none  uuid: b6a97e55-1a85-4175-9fd8-3f3a623d527b
Total devices 1 FS bytes used 142.48GiB
devid    1 size 195.31GiB used 195.31GiB path /dev/sda5

sudo btrfs fi df /media/ubuntu/b6a97e55-1a85-4175-9fd8-3f3a623d527b/
Data, single: total=193.56GiB, used=141.15GiB
System, single: total=4.00MiB, used=48.00KiB
Metadata, single: total=1.75GiB, used=1.29GiB
GlobalReserve, single: total=512.00MiB, used=39.28MiB

sudo btrfs fi balance start -dusage=5 /media/ubuntu /b6a97e55-1a85-4175-9fd8-3f3a623d527b/
ERROR: error during balancing '/media/ubuntu/b6a97e55-1a85-4175-9fd8-3f3a623d527b/': No space left on device
There may be more info in syslog - try dmesg | tail

dmesg | tail
[ 3059.160230] BTRFS info (device sda5): disk space caching is enabled
[ 3059.203601] BTRFS info (device sda5): detected SSD devices, enabling SSD mode
[ 3059.204291] BTRFS info (device sda5): checking UUID tree
[ 3059.206664] BTRFS warning (device sda5): btrfs_uuid_scan_kthread failed -28
[ 3201.876349] BTRFS info (device sda5): 4 enospc errors during balance

Ubuntu on this partition was totally fine before the windows upgrade.

What can I try to repair the BTRFS partition?

Thanks

Edit : Finally found the solution here at the "Balance cannot run because the filesystem is full" paragraph

Turns out the metadata was full and I had to add an empty device in order to rebalance the FS. No idea why this happened.

Best Answer

Finally found the solution here at the "Balance cannot run because the filesystem is full" paragraph

Turns out the metadata was full and I had to add an empty device in order to rebalance the FS. No idea why this happened.