Re: received uuid not set btrfs send/receive

[Hugo Mills <hugo@carfax.org.uk>]

On Sun, Jan 17, 2021 at 10:49:26AM -0800, Anders Halman wrote:
> Hello,
> 
> I try to backup my laptop over an unreliable slow internet connection to a
> even slower Raspberry Pi.
> 
> To bootstrap the backup I used the following:
> 
> # local
> btrfs send root.send.ro | pigz | split --verbose -d -b 1G
> rsync -aHAXxv --numeric-ids --partial --progress -e "ssh -T -o
> Compression=no -x" x* remote-host:/mnt/backup/btrfs-backup/
> 
> # remote
> cat x* > split.gz
> pigz -d split.gz
> btrfs receive -f split

> worked nicely. But I don't understand why the "received uuid" on the remote
> site in blank.

   Are you doing the receive as root?

   Hugo.

> I tried it locally with smaller volumes and it worked.
> 
> The 'split' file contains the correct uuid, but it is not set (remote).
> 
> remote$ btrfs receive --dump -f split | head
> subvol          ./root.send.ro uuid=99a34963-3506-7e4c-a82d-93e337191684
> transid=1232187
> 
> local$ sudo btrfs sub show root.send.ro| grep -i uuid:
>     UUID:             99a34963-3506-7e4c-a82d-93e337191684
> 
> 
> Questions:
> 
> - Is there a way to set the "received uuid"?
> - Is it a matter of btrfs-progs version difference?
> - What whould be a better approach?
> 
> 
> Thank you
> 
> 
> ----
> 
> # local
> 
> root@fos ~$ uname -a
> Linux fos 5.9.16-200.fc33.x86_64 #1 SMP Mon Dec 21 14:08:22 UTC 2020 x86_64
> x86_64 x86_64 GNU/Linux
> 
> root@fos ~$   btrfs --version
> btrfs-progs v5.9
> 
> root@fos ~$   btrfs fi show
> Label: 'DATA'  uuid: b6e675b3-84e3-4869-b858-218c5f0ac5ad
>     Total devices 1 FS bytes used 402.17GiB
>     devid    1 size 464.27GiB used 414.06GiB path
> /dev/mapper/luks-e4e69cfa-faae-4af8-93f5-7b21b25ab4e6
> 
> root@fos ~$   btrfs fi df /btrfs-root/
> Data, single: total=404.00GiB, used=397.80GiB
> System, DUP: total=32.00MiB, used=64.00KiB
> Metadata, DUP: total=5.00GiB, used=4.38GiB
> GlobalReserve, single: total=512.00MiB, used=0.00B
> 
> 
> # remote
> root@pih:~# uname -a
> Linux pih 5.4.72+ #1356 Thu Oct 22 13:56:00 BST 2020 armv6l GNU/Linux
> 
> root@pih:~#   btrfs --version
> btrfs-progs v4.20.1
> 
> root@pih:~#   btrfs fi show
> Label: 'DATA'  uuid: 6be1e09c-d1a5-469d-932b-a8d1c339afae
>     Total devices 1 FS bytes used 377.57GiB
>     devid    2 size 931.51GiB used 383.06GiB path
> /dev/mapper/luks_open_backup0
> 
> root@pih:~#   btrfs fi df /mnt/backup
> Data, single: total=375.00GiB, used=374.25GiB
> System, DUP: total=32.00MiB, used=64.00KiB
> Metadata, DUP: total=4.00GiB, used=3.32GiB
> GlobalReserve, single: total=512.00MiB, used=0.00B
> 
> 
> dmesg is empty for the time of import/btrfs receive.

-- 
Hugo Mills             | If it ain't broke, hit it again.
hugo@... carfax.org.uk |
http://carfax.org.uk/  |
PGP: E2AB1DE4          |                                                  Foon