problem with xm save in mini-os

problem with xm save in mini-os

[Dietmar Hahn]

Hi,

I try to implement "xm save/restore" on mini-os, but have problems.
What I did:
 - set a watch on xenstore "control/shutdown"
   -> The watch function gets called after typing "xm save domid d.save"
 - read "shutdown" from xenstore "control/shutdown"
 - sleep(5s)
 - write "" into xenstore "control/shutdown"
 - sleep(5s)
 - call HYPERVISOR_suspend()
   -> the domain (mini-os) gets terminated.
But the d.save file is to small.

xm log output:
...
[2007-03-15 09:56:18 13150] INFO (XendDomain:1053) Domain Mini-OS1 (22) unpaused.
[2007-03-15 09:56:36 13150] DEBUG (XendCheckpoint:93) [xc_save]: /usr/lib/xen/bin/xc_save 25 22 0 0 0
[2007-03-15 09:56:36 13150] DEBUG (XendCheckpoint:304) suspend
[2007-03-15 09:56:36 13150] DEBUG (XendCheckpoint:96) In saveInputHandler suspend
[2007-03-15 09:56:36 13150] DEBUG (XendConfig:1287) update_with_image_sxp([\047linux\047, [\047kernel\047, \047/root/mini-os.gz\047], [\047args\047, \047Hallo Mini-OS1\047], [\047notes\047]])
[2007-03-15 09:56:36 13150] DEBUG (XendDomainInfo:808) Storing domain details: {\047console/ring-ref\047: \0471177329\047, \047console/port\047: \0472\047, \047name\047: \047migrating-Mini-OS1\047, \047console/limit\047: \0471048576\047, \047vm\047: \047/vm/e58f3a8a-8ed2-66cd-518d-9b2d41506cb3\047, \047domid\047: \04722\047, \047cpu/0/availability\047: \047online\047, \047memory/target\047: \04765536\047, \047control/platform-feature-multiprocessor-suspend\047: \0471\047, \047store/ring-ref\047: \0471177330\047, \047store/port\047: \0471\047}
[2007-03-15 09:56:36 13150] DEBUG (XendCheckpoint:98) Suspending 22 ...
[2007-03-15 09:56:36 13150] DEBUG (XendDomainInfo:432) XendDomainInfo.shutdown(suspend)
[2007-03-15 09:56:36 13150] DEBUG (XendDomainInfo:875) XendDomainInfo.handleShutdownWatch
[2007-03-15 09:56:41 13150] DEBUG (XendDomainInfo:875) XendDomainInfo.handleShutdownWatch
[2007-03-15 09:56:46 13150] INFO (XendCheckpoint:103) Domain 22 suspended.
[2007-03-15 09:56:46 13150] INFO (XendDomainInfo:1056) Domain has shutdown: name=migrating-Mini-OS1 id=22 reason=?.
[2007-03-15 09:56:46 13150] DEBUG (XendCheckpoint:112) Written done
[2007-03-15 09:56:46 13150] INFO (XendCheckpoint:333) ERROR Internal error: Retry suspend domain
[2007-03-15 09:56:46 13150] DEBUG (XendDomainInfo:1620) XendDomainInfo.destroy: domid=22
[2007-03-15 09:56:46 13150] DEBUG (XendDomainInfo:1631) XendDomainInfo.destroyDomain(22)
[2007-03-15 09:56:46 13150] INFO (XendCheckpoint:333) ERROR Internal error: Retry suspend domain
[2007-03-15 09:56:46 13150] INFO (XendCheckpoint:333) ERROR Internal error: domain is dying
[2007-03-15 09:56:46 13150] INFO (XendCheckpoint:333) ERROR Internal error: Domain appears not to have suspended
[2007-03-15 09:56:46 13150] INFO (XendCheckpoint:333) Save exit rc=1
[2007-03-15 09:56:46 13150] ERROR (XendCheckpoint:145) Save failed on domain Mini-OS1 (None).
Traceback (most recent call last):
  File "//usr/lib/python/xen/xend/XendCheckpoint.py", line 114, in save
    forkHelper(cmd, fd, saveInputHandler, False)
  File "//usr/lib/python/xen/xend/XendCheckpoint.py", line 321, in forkHelper
    raise XendError("%s failed" % string.join(cmd))
XendError: /usr/lib/xen/bin/xc_save 25 22 0 0 0 failed
[2007-03-15 09:56:46 13150] DEBUG (XendDomainInfo:1651) XendDomainInfo.resumeDomain(None)
[2007-03-15 09:56:46 13150] DEBUG (XendCheckpoint:148) XendCheckpoint.save: resumeDomain

In the log the 5s sleeps are good visible.
Can anybody give me a hint where to look for the problem?
Thanks.

Dietmar