RE: [Xen-users] Increasing the number of virtual machines

[Stephen Liu <satimis@xxxxxxxxx>]

--- Fred Zinsli <fred.zinsli@xxxxxxxxxxxxx> wrote:

> With the aid of comments here, and some help in #debian (IRC) I have
> found
> out that the kernel I was using for my xen host was compiled without
> loop
> support and hence it would never see more than 4 doms. I didn't
> compile my
> own kernel as I don't have that experience, and getting to grips with
> virtualization on its own is proving to be a big enough task.
> 
> Many thanks for the comments and advice.
> 
> I am now setting up my doms again on the rebuilt server and I will
> see how
> that tests.
> 
> Regards



Hi Fred,


Please try on menu.lst of the host;


# cat /boot/grub/menu.lst
.....
title           Xen 3.1.0 / Debian GNU/Linux, kernel 2.6.18-xen
root            (hd0,0)
kernel          /boot/xen-3.1.0.gz
module          /boot/vmlinuz-2.6.18-xen root=/dev/sda1 ro console=tty0
max_loop=64
module          /boot/initrd.img-2.6.18-xen
savedefault
.....


Add "max_loop=64" to the end of the line "module ...." as above. 
Restart the PC.  Then you can run at lease 30 guests simultaneously if
the loop is NOT run by other devices.


HTH


B.R.
Stephen L







> 
> -----Original Message-----
> From: "James Harper" <james.harper@xxxxxxxxxxxxxxxx>
> To: <fred.zinsli@xxxxxxxxxxxxx>, <xen-users@xxxxxxxxxxxxxxxxxxx>
> Cc: 
> Date: Tue, 2 Dec 2008 20:21:39 +1100
> Subject: RE: [Xen-users] Increasing the number of virtual machines
> 
> > > All of the doms create without error.
> > > I can start them all in the normal way. No errors
> > > When I do xm list I only see the first 4 doms I created.
> > > I can ping only the first 4 doms I created.
> > > I can only enter the console of the first 4 doms I created.
> > > 
> > > I have used this howto as a starting point for my solution.
> > > http://www.howtoforge.com/perfect_setup_xen3_debian
> > > 
> > > There are no errors generated to the screen or log files that I
> can
> > find.
> > > 
> > 
> > As someone else pointed out, 4 is the default limit for the number
> of
> > loop devices (loop makes a block device out of a file), and your
> domain
> > will use one for every file: device in every domain, which may or
> may
> > not be your problem.
> > 
> > If loop is a module, stop all of your domains, 'rmmod loop', then
> > 'modprobe loop max_loop=32', then see how many you can start. If
> that
> > fixes it, then edit your modules config to always load loop with
> > max_loop=32
> > 
> > James
> > 
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-users
> 
> 
> 
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
> 


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