[Lxc-users] lxc containers as backup 'replicas'

[Rory Campbell-Lange]

On 05/06/13, Fajar A. Nugraha (list at fajar.net) wrote:
> On Wed, Jun 5, 2013 at 6:50 PM, Rory Campbell-Lange
> <rory at campbell-lange.net> wrote:

> > I'd be grateful to know if it is possible to sync 1. and 3. into the
> > container when it is not running. In other words, to simply update the
> > config files in /var/lib/lxc/<container>/rootfs/etc, for example?
...
> However, personally I'd just forget for a moment that the backup will be
> run on lxc and do the same things I'd do on a normal machine.
> 
> In my case, I'd use zfs snapshot and send|receive (yes, you can use zfs
> for root). In your case it'd probably be rsync or whatever you're happy with.

Are there any files that shouldn't percolate between a normal running
server's /etc/ and one in an lxc container?

> > On another point I'd also like to know of the recommended way of using
> > another mount point for lxc containers and the dpkg cache. For example,
> > I wish to hold my containers in /dev/sdb/ mounted on /containers. Should
> > I symlink /var/lib/lxc/ to this mount point?
> 
> I'm pretty sure there were problems wiith that on some versions on lxc
> (can't remember the exact details, sorry). A bind mount would probably
> be safer.

do you mean the exivalent of 'mount /dev/sdb1 /var/lib/lxc/' ?

> > Finally I'd be grateful to learn of people's experiences with btrfs for
> > snapshotting and managing containers. I personally use it for my laptop
> > backups, but my host server is on a 3.2.0-4-amd64 kernel which is pretty
> > old by btrfs standards.
> 
> Is there a particular requirement for that version of kernel? In
> RHEL/Centos/Ubuntu you can often use prebuilt latest vanilla kernel
> with only minimum change required (although the distro won't offically
> support it, obviously).
> 
> If you're stuck with kernel 3.2 then I'd say use zfs. The devs take extra
> care to make sure it works well on RHEL6 (with its ancient 2.6.32 kernel),
> and should work on all kernel from that version up to 3.9.

I'm on Debian stable and I like being there for production machines
(even though this is a backup machine). I'm not sure about the
availability of a 3.8+ kernel on Debian.

I'm tempted by zfs but worried about its likely cohabitation --
licence-wise -- over time with the kernel. 

Thanks for your comments
Rory

-- 
Rory Campbell-Lange
rory at campbell-lange.net