Re: [Xen-users] Issues migrating to xen 4.1 / lvm vg for disk

Re: [Xen-users] Issues migrating to xen 4.1 / lvm vg for disk

[Pasi Kärkkäinen]

On Sun, Apr 10, 2011 at 12:56:05PM +0800, Sylvain CHEVALIER wrote:
> Hi,
> 
> We just migrated xen on gentoo on amd64 from 4.0 to 4.1 and
> encountered a few issues that were not documented. Here is how we
> solved them and what issues are remaining:
> 
> 1. Our config files were referring to the LVM devices like
> /dev/vg/domU-root with disk = [ 'phy:vg/domU-root,sda1,w' ]. This does
> not work anymore, we have to include '/dev/': disk = [
> 'phy:/dev/vg/domU-root,sda1,w' ].
> 

Hello,

I added xen-devel to CC list. 
(I'll reply your other questions on another email.)

-- Pasi

Re: [Xen-users] Issues migrating to xen 4.1 / qemu-dm memory leak?

[Pasi Kärkkäinen]

On Mon, Apr 11, 2011 at 08:41:59AM +0800, Sylvain CHEVALIER wrote:
> > And did you mean qemu-dm process in dom0 is leaking memory?
> >
> 
> I believe so. After running the whole week-end, with one instance of
> windows 2008 used as a domain controller, qemu-dm uses 2GB of RAM.
> Running pmap, I am getting lots of lines like this one:
> 
> 00007fcd73f2e000   1024K rw-s-  /proc/xen/privcmd
> 
> $ pmap 10423| grep /proc/xen/privcmd | wc -l
> 1827
> 
> Any clue?
> 

Ok. So, a summary:

- VM has 512 MB of memory: qemu-dm leaks memory.
- VM has 4GB of memory: qemu-dm doesn't leak memory.

Is that what you meant?

btw. is that Windows running any PV drivers or pure HVM with emulated devices?

-- Pasi

Re: Issues migrating to xen 4.1 / qemu-dm memory leak?

[Sylvain CHEVALIER]

> Ok. So, a summary:
>
> - VM has 512 MB of memory: qemu-dm leaks memory.
> - VM has 4GB of memory: qemu-dm doesn't leak memory.
>
> Is that what you meant?

Oups, I am sorry, I am realizing that I made a typo in my original
message, I am only talking about dom0, not the VM. qemu-dm is leaking
memory, so if I only allocate 512MB to dom0 it will quickly run out of
memory. When I allocate more (4GB), I do not run out. At least until
now.

>
> btw. is that Windows running any PV drivers or pure HVM with emulated devices?
>

Pure HVM with emulated devices with qemu, I haven't looked at PV drivers.

Sylvain

Re: Re: [Xen-users] Issues migrating to xen 4.1 / lvm vg for disk

[Pasi Kärkkäinen]

Hello,

(added Ian as CC).

While talking about supported disk configuration syntax,
I remembered this report again..

Sylvain: Did you use 'xl' or 'xm' ?

-- Pasi

On Sun, Apr 10, 2011 at 10:26:22PM +0300, Pasi Kärkkäinen wrote:
> On Sun, Apr 10, 2011 at 12:56:05PM +0800, Sylvain CHEVALIER wrote:
> > Hi,
> > 
> > We just migrated xen on gentoo on amd64 from 4.0 to 4.1 and
> > encountered a few issues that were not documented. Here is how we
> > solved them and what issues are remaining:
> > 
> > 1. Our config files were referring to the LVM devices like
> > /dev/vg/domU-root with disk = [ 'phy:vg/domU-root,sda1,w' ]. This does
> > not work anymore, we have to include '/dev/': disk = [
> > 'phy:/dev/vg/domU-root,sda1,w' ].
> > 
> 
> Hello,
> 
> I added xen-devel to CC list. 
> (I'll reply your other questions on another email.)
> 
> -- Pasi
> 

Re: Re: [Xen-users] Issues migrating to xen 4.1 / qemu-dm memory leak?

[Pasi Kärkkäinen]

On Mon, Apr 11, 2011 at 09:54:27AM +0300, Pasi Kärkkäinen wrote:
> On Mon, Apr 11, 2011 at 08:41:59AM +0800, Sylvain CHEVALIER wrote:
> > > And did you mean qemu-dm process in dom0 is leaking memory?
> > >
> > 
> > I believe so. After running the whole week-end, with one instance of
> > windows 2008 used as a domain controller, qemu-dm uses 2GB of RAM.
> > Running pmap, I am getting lots of lines like this one:
> > 
> > 00007fcd73f2e000   1024K rw-s-  /proc/xen/privcmd
> > 
> > $ pmap 10423| grep /proc/xen/privcmd | wc -l
> > 1827
> > 
> > Any clue?
> > 
> 
> Ok. So, a summary:
> 
> - VM has 512 MB of memory: qemu-dm leaks memory.
> - VM has 4GB of memory: qemu-dm doesn't leak memory.
> 
> Is that what you meant?
> 
> btw. is that Windows running any PV drivers or pure HVM with emulated devices?
> 

Hello again,

Sylvain: Are you still seeing this qemu-dm memleak problem? Did you resolve it? 

-- Pasi

Re: Re: [Xen-users] Issues migrating to xen 4.1 / lvm vg for disk

[Sylvain CHEVALIER]

Hi Pasi,

Thanks a lot for following up. We had to change this part of our
config files when we moved from xm to xl.

Sylvain

On Fri, Apr 29, 2011 at 3:33 AM, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> Hello,
>
> (added Ian as CC).
>
> While talking about supported disk configuration syntax,
> I remembered this report again..
>
> Sylvain: Did you use 'xl' or 'xm' ?
>
> -- Pasi
>
> On Sun, Apr 10, 2011 at 10:26:22PM +0300, Pasi Kärkkäinen wrote:
>> On Sun, Apr 10, 2011 at 12:56:05PM +0800, Sylvain CHEVALIER wrote:
>> > Hi,
>> >
>> > We just migrated xen on gentoo on amd64 from 4.0 to 4.1 and
>> > encountered a few issues that were not documented. Here is how we
>> > solved them and what issues are remaining:
>> >
>> > 1. Our config files were referring to the LVM devices like
>> > /dev/vg/domU-root with disk = [ 'phy:vg/domU-root,sda1,w' ]. This does
>> > not work anymore, we have to include '/dev/': disk = [
>> > 'phy:/dev/vg/domU-root,sda1,w' ].
>> >
>>
>> Hello,
>>
>> I added xen-devel to CC list.
>> (I'll reply your other questions on another email.)
>>
>> -- Pasi
>>
>
>

Re: Re: [Xen-users] Issues migrating to xen 4.1 / qemu-dm memory leak?

[Sylvain CHEVALIER]

Hi Pasi,

I think it does leak memory although I am not completely sure. What I
am seeing is that it uses almost 2GB of memory, and that it is
(slowly) growing. Before we updated to xen 4.1 (which included a qemu
update), we only had 512MB for dom0.

Right now, we have (24576 is qemu's pid):

$ pmap 24576
total          1765848K
$ pmap 24576 | grep /proc/xen/privcmd | wc -l
1624

Thanks,

Sylvain

On Fri, Apr 29, 2011 at 3:42 AM, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> On Mon, Apr 11, 2011 at 09:54:27AM +0300, Pasi Kärkkäinen wrote:
>> On Mon, Apr 11, 2011 at 08:41:59AM +0800, Sylvain CHEVALIER wrote:
>> > > And did you mean qemu-dm process in dom0 is leaking memory?
>> > >
>> >
>> > I believe so. After running the whole week-end, with one instance of
>> > windows 2008 used as a domain controller, qemu-dm uses 2GB of RAM.
>> > Running pmap, I am getting lots of lines like this one:
>> >
>> > 00007fcd73f2e000   1024K rw-s-  /proc/xen/privcmd
>> >
>> > $ pmap 10423| grep /proc/xen/privcmd | wc -l
>> > 1827
>> >
>> > Any clue?
>> >
>>
>> Ok. So, a summary:
>>
>> - VM has 512 MB of memory: qemu-dm leaks memory.
>> - VM has 4GB of memory: qemu-dm doesn't leak memory.
>>
>> Is that what you meant?
>>
>> btw. is that Windows running any PV drivers or pure HVM with emulated devices?
>>
>
> Hello again,
>
> Sylvain: Are you still seeing this qemu-dm memleak problem? Did you resolve it?
>
> -- Pasi
>
>

Re: Re: [Xen-users] Issues migrating to xen 4.1 / lvm vg for disk

[Ian Campbell]

> >> On Sun, Apr 10, 2011 at 12:56:05PM +0800, Sylvain CHEVALIER wrote:
> >> > 1. Our config files were referring to the LVM devices like
> >> > /dev/vg/domU-root with disk = [ 'phy:vg/domU-root,sda1,w' ]. This does
> >> > not work anymore, we have to include '/dev/': disk = [
> >> > 'phy:/dev/vg/domU-root,sda1,w' ].

This seems like a bug in xl's implementation of the syntax specification
(docs/misc/xl-disk-configuration.txt), which states that any path which
doesn't start with a / should have "/dev/" prepended (IOW non-absolute
paths are relative to /dev/).

Anyone fancy knocking up a patch?

Ian.