[libvirt] Re: the <filesystem> tag (WAS: simple LXC/libvirt busybox container (Unable to get cgroup))

[Tony Risinger]

That all sounds great.  wanted to say libvirt has been very useful to
my personal projects as well as the former company i worked for;
thanks to everyone invloved, its a great product!  on a final note,
any chance there is a way to get libvirt to trigger an arbitrary
script (like the network scripts) that could handle this mount for me?
 didnt see anything like that in docs but i figured i'd ask anyway.

thanks again for all the great work.

On Fri, Dec 11, 2009 at 4:20 AM, Daniel P. Berrange <berrange at redhat.com> wrote:
> On Thu, Dec 10, 2009 at 05:44:30PM -0600, Tony Risinger wrote:
>> wow!  i was starting to think i would never get past this problem!
>>
>> [root at PHS-001 ~]# echo $VIRSH_DEFAULT_CONNECT_URI
>> lxc:///
>>
>> [root at PHS-001 ~]# virsh create /vps/def/exec/sys/arch-nano.xml
>> Domain arch-nano created from /vps/def/exec/sys/arch-nano.xml
>>
>> [root at PHS-001 ~]# virsh console arch-nano
>> Connected to domain arch-nano
>> Escape character is ^]
>> #
>>
>> [root at PHS-001 ~]# grep cgroup /proc/mounts
>> none /cgroup cgroup rw,relatime,devices,memory,cpuacct,cpu 0 0
>>
>> everything seems to be working fine now after disabling "ns" from
>> cgroup mount; thank you very much Ryota and Daniel for you time and
>> assistance.  i must have sunk 40+ hours into this, but i learned a
>> tremendous amount, so nothing is lost. :-)
>>
>> this is somewhat of a digression, and i can submit a new thread if
>> need be, but my last remaining question is about the <filesystem>
>> tag/root mounting.  i have not found any mention of the <filesystem>
>> tag in the docs or how to work with it... i want to have libvirt mount
>> a specified device (a btrfs subvolume) and use it for the root
>> filesystem of the created LXC container.  is there a way to do this?
>> perhaps <source dev="/dev/sdb" options="subvol....."/>, or do i need
>> to use the storage XML?  i didnt see a way to use a storage/device
>> definition as the rootfs.
>
> The plan is that the <filesystem> tag will eventually support 3 types
> of sources, a directory (which gets bind mounted into the root),
> a file (loopback device + mounted), or block device (directly mounted).
> Currently though we only support the first option. So if you have a
> block device, you should first mount it in your host OS, and then let
> LXC bind the mount point into the container.
>
> Regards,
> Daniel
> --
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