Re: [RFC v7][PATCH 0/9] Kernel based checkpoint/restart

[Daniel Lezcano]

Ingo Molnar wrote:
> * Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> wrote:
>
> > On Tue, 2008-10-21 at 12:21 -0700, Andrew Morton wrote:
> > > On Mon, 20 Oct 2008 01:40:28 -0400
> > > Oren Laadan <orenl@xxxxxxxxxxxxxxx> wrote:
> > > > These patches implement basic checkpoint-restart [CR]. This version
> > > > (v7) supports basic tasks with simple private memory, and open files
> > > > (regular files and directories only).
> > > - how useful is this code as it stands in real-world usage?
> > Right now, an application must be specifically written to use these 
> > mew system calls.  It must be a single process and not share any 
> > resources with other processes.  The only file descriptors that may be 
> > open are simple files and may not include sockets or pipes.
> >
> > What this means in practice is that it is useful for a simple app 
> > doing computational work.
>
> say a chemistry application doing calculations. Or a raytracer with a 
> large job. Both can take many hours (days!) even on very fast machine 
> and the restrictions on rebootability can hurt in such cases.
>
> You should reach a minimal level of initial practical utility: say some 
> helper tool that allows testers to checkpoint and restore a real PovRay 
> session - without any modification to a stock distro PovRay.

There are the liblxc userspace tools doing that.

http://sourceforge.net/projects/lxc/

There are the lxc-checkpoint and lxc-restart commands to test the Oren's 
patches with the external checkpoint Cedric did. These commands are 
experimental and under development so a hack may be necessary for 
checkpoint/restart.

I didn't tried with Oren's external checkpoint yet, but I think the 
commands should work. Actually these commands relies on the freezer, so 
the checkpoint command does freeze, checkpoint, unfreeze. (and kill if 
specified).

	lxc-create -n foo

	lxc-start -n foo mypovray

	lxc-checkpoint -s -n foo > myckptfile

	lxc-restart -n foo < myckptfile

Thanks
  -- Daniel
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/