Xen 3.1 - migration fail / save/restore of PV guests too

Xen 3.1 - migration fail / save/restore of PV guests too

[Sébastien Riccio]

Hi,

I'm currently playing with Xen 3.1 live migration and save/restore features.
I tried to migrate and save/restore a 32p domain on a 64 host and both 
fails.

When I attemp to "xm save centos5 centos.save" xend.log reports this:
(I guess if xm save doesn't work, (live) migrations won't either).

[2007-05-26 17:20:03 3206] DEBUG (XendCheckpoint:88) [xc_save]: 
/usr/lib64/xen/bin/xc_save 22 3 0 0 0
[2007-05-26 17:20:03 3206] DEBUG (XendDomainInfo:824) Storing domain 
details: {'console/ring-ref': '254742', 'image/en
try': '3222274048', 'console/port': '2', 'store/ring-ref': '254743', 
'image/loader': 'generic', 'vm': '/vm/06ed00fe-11
62-4fc4-b5d8-11993ee4a8b9', 
'control/platform-feature-multiprocessor-suspend': '1', 
'image/hv-start-low': '4118806528'
, 'image/guest-os': 'linux', 
'image/features/writable-descriptor-tables': '1', 'image/virt-base': 
'3221225472', 'memor
y/target': '524288', 'image/guest-version': '2.6', 
'image/features/supervisor-mode-kernel': '1', 'image/pae-mode': 'ye
s', 'console/limit': '1048576', 'image/paddr-offset': '0', 
'image/hypercall-page': '3222278144', 'image/suspend-cancel
': '1', 'cpu/0/availability': 'online', 
'image/features/pae-pgdir-above-4gb': '1', 
'image/features/writable-page-table
s': '1', 'image/features/auto-translated-physmap': '1', 'name': 
'migrating-centos5', 'domid': '3', 'image/xen-version'
: 'xen-3.0', 'store/port': '1'}
[2007-05-26 17:20:03 3206] DEBUG (XendCheckpoint:320) suspend
[2007-05-26 17:20:03 3206] DEBUG (XendCheckpoint:91) In saveInputHandler 
suspend
[2007-05-26 17:20:03 3206] DEBUG (XendCheckpoint:93) Suspending 3 ...
[2007-05-26 17:20:03 3206] DEBUG (XendDomainInfo:443) 
XendDomainInfo.shutdown(suspend)
[2007-05-26 17:20:03 3206] DEBUG (XendDomainInfo:908) 
XendDomainInfo.handleShutdownWatch
[2007-05-26 17:20:03 3206] DEBUG (XendDomainInfo:908) 
XendDomainInfo.handleShutdownWatch
[2007-05-26 17:20:03 3206] INFO (XendCheckpoint:98) Domain 3 suspended.
[2007-05-26 17:20:03 3206] INFO (XendDomainInfo:1090) Domain has 
shutdown: name=migrating-centos5 id=3 reason=suspend.
[2007-05-26 17:20:03 3206] DEBUG (XendCheckpoint:107) Written done
[2007-05-26 17:20:05 3206] INFO (XendCheckpoint:349) ERROR Internal 
error: Timed out waiting for frame list updated.
[2007-05-26 17:20:05 3206] INFO (XendCheckpoint:349) ERROR Internal 
error: Failed to map/save the p2m frame list
[2007-05-26 17:20:05 3206] INFO (XendCheckpoint:349) Save exit rc=1
[2007-05-26 17:20:05 3206] ERROR (XendCheckpoint:140) Save failed on 
domain centos5 (3).
Traceback (most recent call last):
  File "/usr/lib64/python/xen/xend/XendCheckpoint.py", line 109, in save
    forkHelper(cmd, fd, saveInputHandler, False)
  File "/usr/lib64/python/xen/xend/XendCheckpoint.py", line 337, in 
forkHelper
    raise XendError("%s failed" % string.join(cmd))
XendError: /usr/lib64/xen/bin/xc_save 22 3 0 0 0 failed
[2007-05-26 17:20:05 3206] DEBUG (XendDomainInfo:1699) 
XendDomainInfo.resumeDomain(3)
[2007-05-26 17:20:05 3206] DEBUG (XendCheckpoint:143) 
XendCheckpoint.save: resumeDomain
[2007-05-26 17:21:24 3206] DEBUG (XendDomainInfo:1660) 
XendDomainInfo.destroy: domid=3
[2007-05-26 17:21:24 3206] DEBUG (XendDomainInfo:1677) 
XendDomainInfo.destroyDomain(3)

Any idea what could be the problem ?

I tried both with source and binary tarballs and with latest mercurial 
build too....

Thank you for your answers.

Sébastien

Re: Xen 3.1 - migration fail / save/restore of PV guests too

[Tomasz Chmielewski]

Sébastien Riccio schrieb:
> Hi,
> 
> I'm currently playing with Xen 3.1 live migration and save/restore 
> features.
> I tried to migrate and save/restore a 32p domain on a 64 host and both 
> fails.
> 
> When I attemp to "xm save centos5 centos.save" xend.log reports this:
> (I guess if xm save doesn't work, (live) migrations won't either).

(...)

> Any idea what could be the problem ?

See dmesg/kernel logs, too.

Lately, I had a similar problem - it appeared that saving PV guests 
needs much more memory in dom0 (may depend on memory used by domU).


-- 
Tomasz Chmielewski
http://wpkg.org

Re: Xen 3.1 - migration fail / save/restore of PV guests too

[Keir Fraser]

On 26/5/07 16:57, "Sébastien Riccio" <sr@swisscenter.com> wrote:

> I'm currently playing with Xen 3.1 live migration and save/restore features.
> I tried to migrate and save/restore a 32p domain on a 64 host and both
> fails.

Because of different layouts and sizes of certain structures for 32-bit
versus 64-bit guests, save/restore/migrate currently only works where the
domU is the same 'bitness' as your dom0. This restriction does not apply to
HVM domUs, only PV domUs. We hope to lift the restriction for Xen 3.1.1.

32-on-64 is one of the 'harder' new features in 3.1.0, so it will take a
little while to beat out the last few bugs and feature regressions!

 -- Keir

Re: Xen 3.1 - migration fail / save/restore of PV guests too

[Sébastien Riccio]

Hi,

Okay I see :) I will meanwhile play with 64bit domU migrations then.

Thanks a lot for your answer.

Sébastien

Keir Fraser a écrit :
> On 26/5/07 16:57, "Sébastien Riccio" <sr@swisscenter.com> wrote:
>
>   
>> I'm currently playing with Xen 3.1 live migration and save/restore features.
>> I tried to migrate and save/restore a 32p domain on a 64 host and both
>> fails.
>>     
>
> Because of different layouts and sizes of certain structures for 32-bit
> versus 64-bit guests, save/restore/migrate currently only works where the
> domU is the same 'bitness' as your dom0. This restriction does not apply to
> HVM domUs, only PV domUs. We hope to lift the restriction for Xen 3.1.1.
>
> 32-on-64 is one of the 'harder' new features in 3.1.0, so it will take a
> little while to beat out the last few bugs and feature regressions!
>
>  -- Keir
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
>