[Lxc-users] Mount error when shutting down a container

[Serge Hallyn]

Quoting Jean-François Leroux (leroux.jeanfrancois at gmail.com):
> Hi,
> 
> I'm trying lxc on Ubuntu server 12.04 LTS. One thing that concerns me is 
> the error message when issuing a halt command from inside a container 
> (either squeeze container or ubuntu):
> 
> Squeeze:
> mount: cannot mount block device rootfs read-only
> 
> Ubuntu :
> mount: cannot mount block device 
> /dev/disk/by-uuid/b6480bce-bd88-4f83-a45d-786b17161dca read-only
> 
> It seems the container wants to mount the host filesystem read-only...
> 
> Is there a way to correct that or something I'm doing wrong?

It's nothing to worry about.  Userspace tries to remount the hostfs
read-only at shutdown.  But in a normal directory-backed container,
allowing it to do so would mean that that your host rootfs could
end up being remounted read-only.  That's undesirable :)

-serge