[Lxc-users] lxc-start: Device or resource busy - could not unmount old rootfs

[Serge E. Hallyn]

Quoting Pier Fumagalli (pier at betaversion.org):
> On Thu, Apr 15, 2010 at 01:39, Matt Bailey <mbailey at system42.net> wrote:
> 
> Those are also the instructions I followed.  The only difference I can
> > see is that I have a separate volume for /var on my host.
> >
> 
> Oh, interesting: I too have a separate partition for /var/ .... Sorry for
> not reporting this at first!
> 
>     Pier

[ summary: lxc git fixes this ]

Heh, all right, I was able to reproduce after create a new VM with /var
on separate partition.  (was delayed bc there is a bug in kvm or lucid
installer causing install to die if /var is on separate disk!)

strace -f -o/tmp/ab lxc-start -n lucid1 shows umount(/) is returning
-EBUSY.  Which actually doesn't make a lot of sense bc /var *was*
successfully unmounted.  But in any case as Brian White was saying,
commit c08556c6ece8ad8308f7636adb0ad25b60e3a16d in lxc git, which is
not in 0.6.5, is the one making it use MNT_DETACH.

And, in fact, installing lxc from git lets the same container succeed
on the host where it fails with lxc 0.6.5.

So looks like beside downgrading you also have the option of upgrading :)

-serge