i have a dedicated server with Ubuntu 15 Wily and i want to play/study with LXC. My main goal is to snapshot and clone containers without stopping them, and for so i have formatted a partition with BTRFS file sistem.
root@lxc:/btrfs-partition/lxc-subvolume02# btrfs subvolume list /btrfs-partition/
ID 256 gen 10 top level 5 path ext2_saved
ID 260 gen 34 top level 5 path lxc-subvolume
ID 261 gen 745 top level 5 path lxc-subvolume02
ID 262 gen 740 top level 261 path lxc-subvolume02/www05btrfs/rootfs
ID 263 gen 740 top level 261 path lxc-subvolume02/www05btrfs/snaps/snap0/rootfs
this is the partition layout where "/btrfs-partition" it the btrfs forlder mounted
ID 262 gen 740 top level 261 path lxc-subvolume02/www05btrfs/rootfs
this container has been created with this command:
lxc-create -B btrfs -n www05btrfs -t debian -- -r wheezy -a amd64
when i have tried to take a snapshot:
lxc-snapshot -n www05btrfs
i have received this error:
lxc-snapshot: lxccontainer.c: do_lxcapi_clone: 2795 error: Original container (www05btrfs) is running
lxc-snapshot: lxccontainer.c: do_lxcapi_snapshot: 3113 clone of /btrfs-partition/lxc-subvolume02:www05btrfs failed
lxc-snapshot: lxc_snapshot.c: do_snapshot: 55 Error creating a snapshot
I thought that i have first to create a comment file, so i have:
echo "some comment bla bla bla" > snap-comment
lxc-snapshot -n www05btrfs -c snap-comment
but same error:
lxc-snapshot: lxccontainer.c: do_lxcapi_clone: 2795 error: Original container (www05btrfs) is running
lxc-snapshot: lxccontainer.c: do_lxcapi_snapshot: 3113 clone of /btrfs-partition/lxc-subvolume02:www05btrfs failed
lxc-snapshot: lxc_snapshot.c: do_snapshot: 55 Error creating a snapshot
but if i stop the container and create a comment everything works:
root@lxc:/btrfs-partition/lxc-subvolume02# lxc-stop -n www05btrfs
root@lxc:/btrfs-partition/lxc-subvolume02# lxc-snapshot -n www05btrfs -c snap-comment
root@lxc:/btrfs-partition/lxc-subvolume02# lxc-start -n www05btrfs
root@lxc:/btrfs-partition/lxc-subvolume02# lxc-snapshot -n www05btrfs -L -C
snap0 (/btrfs-partition/lxc-subvolume02/www05btrfs/snaps) 2015:11:08 09:36:26
before installing apache2
So, can anyone help me with a working procedure to snapshot correctly LXC Containers with BTRFS fs?
i have been reading this : https://www.stgraber.org/2013/12/27/lxc-1-0-container-storage/
and this Proper way of handling LXC containers on btrfs
but none works as described. thank you
