xenbsd /netbsd: xennetback: can't get new mcl pages (0)

[Anzi <anzi%dnainternet.net@localhost>]

Hi,

In the weekend I had trouble with netbsd / xen. Console showed following
text and xen guestdomains where not accessible from network. Also Dom0
not allowed ssh login, only ping worked. Finally I had to reboot machine
from powerswitch.
I think that problem started somewhere where automated rootfilesystem
snapshot was being made or copied to NFS.

This was in the /var/log/messages (I copied only the relevant parts):

Mar  4 00:34:01 xenbsd /netbsd: nfs server nfsHOST:/LinuxBackup: not
responding
Mar  4 00:34:01 xenbsd /netbsd: nfs server nfsHOST:/LinuxBackup: is
alive again
Mar  4 00:36:16 xenbsd /netbsd: nfs server nfsHOST:/LinuxBackup: not
responding
Mar  4 00:36:16 xenbsd /netbsd: nfs server nfsHOST:/LinuxBackup: is
alive again
Mar  4 00:39:39 xenbsd /netbsd: nfs server nfsHOST:/LinuxBackup: not
responding
Mar  4 00:39:39 xenbsd /netbsd: nfs server nfsHOST:/LinuxBackup: is
alive again

Mar  4 00:41:13 xenbsd /netbsd: xennetback: got only 14 new mcl pages

Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
Mar  4 00:41:53 xenbsd /netbsd: s
Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
.
.
.
Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages

Mar  4 00:41:53 xenbsd /netbsd: nfs_timer: ignoring error 55

Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
.
.
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
Mar  4 00:41:53 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
.
.
.
Mar  4 00:41:53 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
Mar  4 00:41:53 xenbsd /netbsd: nnetback_ifstart: no mcl_pages
.
.
Mar  4 00:45:23 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:45:23 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
Mar  4 00:45:23 xenbsd /netbsd: xennetback: can't get new mcl pages (0)
Mar  4 00:45:23 xenbsd /netbsd: xennetback_ifstart: no mcl_pages
.
.

Kernel is not default, I have compiled it myself, but I think there are
no exotic things:
NetBSD xenbsd.domain.com 4.0_BETA2 NetBSD 4.0_BETA2 (XEN3_DOM0) #0: Fri
Jan 19 14:46:24 EET 2007
@xenbsd.domain.com:/home/--/current/src/sys/arch/i386/compile/obj/XEN3_DOM0_ 

i386

I also tried Kernel debugger (CTRL+ALT+ESC), but I'm really not sure
what to do there. tried next/continue and this is what I got:
Just before kernel prints xennetback_ifstart: no mcl_pages
this is executed:
Xennetback ifsoftstart+0x76b:ret


This was on a production machine so I couldn't debug more (I rebooted).
Does anybody have Ideas what seems to be wrong?

-Anzi-