Subject: Re: [vserver] Problems with scripts
From: Gustavo <lungpu@gmail.com>
Date: Thu, 16 Aug 2007 10:41:49 -0300
Thu, 16 Aug 2007 10:41:49 -0300
On 8/15/07, Herbert Poetzl <herbert@13thfloor.at> wrote:
>
> On Wed, Aug 15, 2007 at 05:39:36PM -0300, Gustavo wrote:
> > Hi, I'm new in list, my name is Gustavo and I've been testing vservers
> > for some weeks in my work for development and testing, and made
> > some "helpers" too.
>
> > My problem now is with scripts to be located at /etc/vservers/scripts.
> > As I've seen in the "flower page", they are initialize, prepre-start,
> > pre-start, post-stop, postpost-stop, and so on.
>
> > Happens that I'm trying to mount a file as a loop device to be like de
> > block device representing the disk of the vps.
>
> not the best decision (performance wise), but works
> fine (you might want to consider using LVM instead)


I did, but vserver works natively with the guest filesystem into the host
filesystem, without any other separation than the context. My approach is
near lvm but without using it, because I want everything in the same
partition by now, that's why loop devices. I expect performance issues but
I'm expermenting; the idea is to have the guest filesystem as it was in the
host filesystem (the default) but as a mount point.


> Since initialize runs _before_ the fs is mounted, it works fine
> > but unmounting and freeing the loop dev appears to be not so easy
> > because maybe there is a chroot to the vps root dir before running the
> > postpost-stop script.
>
> actually you do not need to care about unmounting it,
> if you mounted it properly (inside the guest namespace)
> as it will get unmounted when the context disappears


Not really, it is unmounted but remains on the mount tab on vserver stop,
and I also need to free the loop device after unmount.

> Do you know any alternative for doing this?
>
> yeah, I would simply put it into the config fstab and
> be done with it, the tolls will automagically mount it
> for you and the kernel will take care of unmounting


would it manage to free the loop?

> (in some days when this finish taking shape, I'll put public the
> > scripts I made to enhance functionality and make easy common
> > creation/modification tasks with vservers)



thanks


On 8/15/07, Herbert Poetzl <herbert@13thfloor.at> wrote:
On Wed, Aug 15, 2007 at 05:39:36PM -0300, Gustavo wrote:
> Hi, I'm new in list, my name is Gustavo and I've been testing vservers
> for some weeks in my work for development and testing, and made
> some "helpers" too.

> My problem now is with scripts to be located at /etc/vservers/scripts.
> As I've seen in the "flower page", they are initialize, prepre-start,
> pre-start, post-stop, postpost-stop, and so on.

> Happens that I'm trying to mount a file as a loop device to be like de
> block device representing the disk of the vps.

not the best decision (performance wise), but works
fine (you might want to consider using LVM instead)

I did, but vserver works natively with the guest filesystem into the host filesystem, without any other separation than the context. My approach is near lvm but without using it, because I want everything in the same partition by now, that's why loop devices. I expect performance issues but I'm expermenting; the idea is to have the guest filesystem as it was in the host filesystem (the default) but as a mount point.
 

> Since initialize runs _before_ the fs is mounted, it works fine
> but unmounting and freeing the loop dev appears to be not so easy
> because maybe there is a chroot to the vps root dir before running the
> postpost-stop script.

actually you do not need to care about unmounting it,
if you mounted it properly (inside the guest namespace)
as it will get unmounted when the context disappears

Not really, it is unmounted but remains on the mount tab on vserver stop, and I also need to free the loop device after unmount.

> Do you know any alternative for doing this?

yeah, I would simply put it into the config fstab and
be done with it, the tolls will automagically mount it
for you and the kernel will take care of unmounting

would it manage to free the loop?

> (in some days when this finish taking shape, I'll put public the
> scripts I made to enhance functionality and make easy common
> creation/modification tasks with vservers)

 
thanks