[systemd-devel] install Fedora systemd-nspawn container on btrfs

[Andrei Borzenkov]

On Thu, Apr 23, 2015 at 2:50 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> On Thu, 23.04.15 13:45, arnaud gaboury (arnaud.gaboury at gmail.com) wrote:
>
>> Not sure what I did wrong, but I can't install/boot my nspawn container.
>> Here is my setup:
>>
>> Archlinux box- updated
>>
>> 1- created 3 btrfs subvol on /dev/sdb1 (SSD). The goal is to manage
>> snapshots easily.
>> no nested subvol.
>> ------------------------------------------
>> # btrfs subvolume list .
>> ID 266 gen 39 top level 5 path rootvol
>> ID 268 gen 41 top level 5 path var
>> ID 269 gen 42 top level 5 path etc
>> # btrfs filesystem show
>> Label: 'poppy-root'  uuid: ef1b44cd-e7b0-4166-b933-e7d4d20a1171
>>     Total devices 1 FS bytes used 64.00KiB
>>     devid    1 size 80.00GiB used 12.00MiB path /dev/sdb1
>> --------------------------------------------------
>>
>> 2 - mount btrfs subvol
>> -------------------------------------------------------------------
>> # mount -t btrfs -o subvol=rootvol /dev/sdb1 /var/lib/machines/enl
>> # mkdir /var/lib/machines/enl/var
>> # mkdir /var/lib/machines/enl/etc
>> # mount -t btrfs -o subvol=etc /dev/sdb1 /var/lib/machines/enl/etc
>> # mount -t btrfs -o subvol=var /dev/sdb1 /var/lib/machines/enl/var
>> --------------------------------------------------------------------
>
> THis isn't really how one would normally use subvolumes. No need to
> mount each subvolume explicitly, they are just special directories...
>

As long as you never clone parent volume (but why use btrfs then?) As
soon as you create clone or snapshot of parent volume, all childs will
be out of place in it unless you explicitly mount them in correct
place in hierarchy.