Dom0 memory size is persistent?

Dom0 memory size is persistent?

[Yoshi. Oguchi]

Hi,

I'm having a problem with increasing dom0 memory size.

I can change Dom0 memory size by setting dom0_mem in grub/menu.lst
and reboot.
However, when I start xend, Dom0 memory size is reset to the
previous size (yes, the memory size BEFORE reboot). 

It seems when xend starts and xenstored is initialized,
the balloon driver adjusts Dom0 memory to the previous size
recorded in xenstored entry 
(/local/domain/0/memory/target @ /var/lib/xenstored/tdb).

Should this entry be initialized at Dom0 boot? 

Re: Dom0 memory size is persistent?

[Matsumoto]

Hi, all

I have the same problem.
The following is additional infomation.

>I can change Dom0 memory size by setting dom0_mem in grub/menu.lstand
reboot.
>However, when I start xend, Dom0 memory size is reset to the
>previous size (yes, the memory size BEFORE reboot). 

I tried to test it.
The result is : 

　1.rm /var/lib/xenstored/tdb
　2.setting dom0_mem=262144, and reboot
　3.At this time, "xm list" show Dom0 is 256MB.
　4.setting dom0_mem=524288, and dom0 is rebooted.
　5.BUT "xm list" remain in 256MB.

　1.rm /var/lib/xenstored/tdb
　2.setting dom0_mem=262144, and reboot
　3.At this time, "xm list" show Dom0 is 256MB.
　4.rm /var/lib/xenstored/tdb
　5.setting dom0_mem=524288, and dom0 is rebooted.
　6.YES "xm list" show Dom0 is 512MB.

I think tdb should be re-create every time dom0 is started.
Am I correct?

Sincerely Yours,
Nakato	

On Wed, 30 Nov 2005 07:54:02 +0900
"Yoshi. Oguchi" <y-oguchi@jp.fujitsu.com> wrote:

> Hi,
> 
> I'm having a problem with increasing dom0 memory size.
> 
> I can change Dom0 memory size by setting dom0_mem in grub/menu.lst
> and reboot.
> However, when I start xend, Dom0 memory size is reset to the
> previous size (yes, the memory size BEFORE reboot). 
> 
> It seems when xend starts and xenstored is initialized,
> the balloon driver adjusts Dom0 memory to the previous size
> recorded in xenstored entry 
> (/local/domain/0/memory/target @ /var/lib/xenstored/tdb).
> 
> Should this entry be initialized at Dom0 boot? 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: Dom0 memory size is persistent?

[Keir Fraser]

On 30 Nov 2005, at 07:52, Matsumoto wrote:

> I think tdb should be re-create every time dom0 is started.
> Am I correct?

Yes, that is a perfectly good fix. We are even thinking about adding an 
init script to our install that will delete the tdb database file 
automatically for you.

  -- Keir

Re: Dom0 memory size is persistent?

[Anthony Liguori]

Keir Fraser wrote:

>
> On 30 Nov 2005, at 07:52, Matsumoto wrote:
>
>> I think tdb should be re-create every time dom0 is started.
>> Am I correct?
>
>
> Yes, that is a perfectly good fix. We are even thinking about adding 
> an init script to our install that will delete the tdb database file 
> automatically for you.

And blow away the entire store?  Why not just blow away the domain 
configuration paths (/local and /vm)?  I thought the /tool path was 
going to persistent across reboots.

Regards,

Anthony Liguori

>  -- Keir
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>

Re: Dom0 memory size is persistent?

[Ewan Mellor]

On Wed, Nov 30, 2005 at 09:01:31AM -0600, Anthony Liguori wrote:

> Keir Fraser wrote:
> 
> >
> >On 30 Nov 2005, at 07:52, Matsumoto wrote:
> >
> >>I think tdb should be re-create every time dom0 is started.
> >>Am I correct?
> >
> >
> >Yes, that is a perfectly good fix. We are even thinking about adding 
> >an init script to our install that will delete the tdb database file 
> >automatically for you.
> 
> And blow away the entire store?  Why not just blow away the domain 
> configuration paths (/local and /vm)?  I thought the /tool path was 
> going to persistent across reboots.

I have changed xenstored to remove /local when it starts, and I have changed
Xend to ignore the maxmem and memory settings for Dom 0 when _it_ starts.
These two things together should be sufficient to ensure that stale data are
not used, while preserving the contents of /tools, /vm etc.  This should solve
your problem.

Cheers,

Ewan.