You need a mountpoint for the btrfs filesystem containing your subvolumes "@" and "@home", which is probably the partition you created the btrfs filesystem. Assuming this partion is "/dev/sdb1", you need to:

1. Add a mountpoint in fstab for the complete btrfs tree (subvolid=0)

/dev/sdb1 /mnt/btr_pool btrfs defaults,subvolid=0

If you want to mount this by-uuid also, check lsblk -f which gives you the corresponding UUID.

When mounted, you should see something like this:

# ls /mnt/btr_pool
@   @home   [...other subvolumes...]

1. In btrbk.conf, use /mnt/btr_pool as volume:

volume /mnt/btr_pool
  subvolume @
    target send-receive [...]
  subvolume @home
    target send-receive [...]

hope this helps,

• Axel

from btrbk.

I have it copied to a computer. Where /dev/sda1, the computer hard drive and /dev/sdb1 disk in USB drive. Is that correct? The configuration certainly works to create the snapshot.

UUID=8 / btrfs defaults,subvol=@ 0 1 (#sda1)
UUID=8 /home btrfs defaults,subvol=@home 0 2 (#sda1)
/dev/sda1 /mnt/btr_pool btrfs defaults,subvolid=0

snapshot_dir btrbk_snapshots

volume /mnt/btr_pool
subvolume @
target send-receive /media/x/backup (#sdb1)
subvolume @home
target send-receive /media/x/backup (#sdb1)

from btrbk.

yes this should work. Don't forget to create your snapshot_dir (mkdir /mnt/btr_pool/btrbk_snapshots). Then run btrbk -v dryrun, and see if everything is created where you want it to.

from btrbk.

Just as it has worked. Many thanks. That helped me alot.
Now I have to mount on the server Subvolumes. I hope that it just works and I can boot normally again.

from btrbk.

@asomer46 what ubuntu version do you use? Did ubuntu installer create one partition on your disk with btrfs and subvolumes "@" and "@home" as described in: "Ubuntu-specific subvolume layout in 11.04 and later" on the ubuntu help page

@asomer46 could you please paste the output of btrfs subvolume list -auq /mnt/btr_pool/ (this would help me to write a little ubuntu howto)

from btrbk.

Hi,

I hope that you are satisfied with it. I would be very happy about the instructions.

Version: Ubuntu 14.04.3 LTS

btrfs subvolume list -auq /mnt/c/btr_pool/
ID 257 gen 18349 top level 5 parent_uuid - uuid 79e40970-2357-4844-9c26-7747194a6e5a path @
ID 258 gen 18349 top level 5 parent_uuid - uuid af76db48-b6dd-5144-b246-e60a09f15743 path @home
ID 289 gen 15934 top level 257 parent_uuid - uuid 208075d8-0371-364e-806e-1c91f93331a5 path <FS_TREE>/@/mnt/c
ID 317 gen 15854 top level 289 parent_uuid - uuid ef742ee5-ee8f-8742-a2dc-bc5ab5bbeeab path <FS_TREE>/@/mnt/c/btr_pool
ID 320 gen 15888 top level 5 parent_uuid 79e40970-2357-4844-9c26-7747194a6e5a uuid 02b4b6d2-83e1-0d4f-931e-84e0175ec669 path btrbk_snapshots/@.20151119
ID 321 gen 15888 top level 5 parent_uuid af76db48-b6dd-5144-b246-e60a09f15743 uuid b0f97ef8-9408-6144-ae0b-1f17a182b842 path btrbk_snapshots/@home.20151119
ID 322 gen 16344 top level 5 parent_uuid 79e40970-2357-4844-9c26-7747194a6e5a uuid 3bce67a0-a7ec-e24d-912d-0a6b6e98638c path btrbk_snapshots/@.20151120
ID 323 gen 16344 top level 5 parent_uuid af76db48-b6dd-5144-b246-e60a09f15743 uuid 95842b53-ca98-d24f-bab1-5193fd41d572 path btrbk_snapshots/@home.20151120

/etc/fstab: static file system information.

Use 'blkid' to print the universally unique identifier for a

device; this may be used with UUID= as a more robust way to name devices

that works even if disks are added and removed. See fstab(5).

/ was on /dev/sdc1 during installation

UUID=xxxxx /               btrfs   defaults,subvol=@ 0       1

/home was on /dev/sdc1 during installation

UUID=xxxxx /home           btrfs   defaults,subvol=@home 0       2

swap was on /dev/sdd5 during installation

UUID=xxxxx none            swap    sw              0       0

thus far, the configuration is unchanged

/dev/sda1 /mnt/a btrfs defaults 0 0

/dev/sdb1 /mnt/b btrfs defaults 0 2
/mnt/b/xx /var/cache/xxxxxx/xx none defaults,bind  0 2
/mnt/b/yy /var/cache/xxxxxx/yy none defaults,bind 0 2

/dev/sdc1 /mnt/c/btr_pool btrfs defaults,subvolid=0

/dev/sdd1 /mnt/d ext4 defaults 0 0

from btrbk.

/etc/btrbk/backup.conf:
snapshot_preserve_daily 14
snapshot_preserve_weekly 0
snapshot_preserve_monthly 0
target_preserve_daily 20
target_preserve_weekly 10
target_preserve_monthly all

The source drive is now 14 snapshots. But on the target can be seen only 21 total snapshots. There is no weekly and monthly backups? Why is that? Are there any log files?

To me it looks like a permission error. The directories include ROOT and have the rights 755.

from btrbk.

Sorry for the late reply...
I can't really tell what's going on, since I'm pretty sure the preserve mechanism works correctly (as it has been there since the beginning and did not change much).

• If you have enabled the transaction_log config option, there is a log.
• If you run btrbk -v dryrun, you get a table showing what's going on in the scheduler, maybe this helps

from btrbk.

No problem due to the delay. "BTR BK -c -V dry run" has helped. Everything works correctly. Thank you.

from btrbk.

I had to use to restore a backup. This was possible. It is however important to know that you have to install the new Bootloader. In the near future I will report on my side about it.

from btrbk.