Xen memory management not working

[Peter Viskup <skupko.sk@gmail.com>]

Hello everyone,
we have issue with memory increase for virtual servers on one of our 
boxes. We are running Debian Squeeze and Xen 4.0.
Looks like after last upgrade of xen-utils-4.0 and xenstore-utils 
without upgrade of xen-hypervisor and linux-image packages the memory 
management stopped working.

server2:~# xm list tis
Name                                        ID   Mem VCPUs      State 
Time(s)
tis                                         62  1024     2     -b---- 
392680.7

server2:~# xm mem-set tis 2048
server2:~# xm list tis
Name                                        ID   Mem VCPUs      State 
Time(s)
tis                                         62  2048     2     -b---- 
392680.9

The target_kb value changed on VPS, but the available memory didn't 
increased for some unknown reason:

tis:~# cat /sys/devices/system/xen_memory/xen_memory0/target_kb
1048576

tis:~# cat /sys/devices/system/xen_memory/xen_memory0/target_kb
2097152

tis:~# grep MemTotal /proc/meminfo
MemTotal:        1044316 kB

Xen packages installed on dom0:

server2:~# dpkg -l | grep xen
ii  libxenstore3.0                          4.0.1-4 
 Xenstore communications library for Xen
ii  linux-image-2.6-xen-amd64               2.6.32+29 
 Linux 2.6 for 64-bit PCs (meta-package), Xen dom0 support
ii  linux-image-2.6.26-2-xen-amd64          2.6.26-26lenny2 
 Linux 2.6.26 image on AMD64, oldstyle Xen support
ii  linux-image-2.6.32-5-xen-amd64          2.6.32-38 
 Linux 2.6.32 for 64-bit PCs, Xen dom0 support
ii  linux-modules-2.6-xen-amd64             2.6.26+17+lenny1 
 Linux 2.6 modules on AMD64
ii  linux-modules-2.6.26-2-xen-amd64        2.6.26-26lenny2 
 Linux 2.6.26 modules on AMD64
ii  xen-hypervisor-3.2-1-amd64              3.2.1-2 
 The Xen Hypervisor on AMD64
ii  xen-hypervisor-4.0-amd64                4.0.1-4 
 The Xen Hypervisor on AMD64
ii  xen-qemu-dm-4.0                         4.0.1-2 
 Xen Qemu Device Model virtual machine hardware emulator
ii  xen-shell                               1.8-3 
 Console based Xen administration utility
ii  xen-tools                               4.2-1 
 Tools to manage Xen virtual servers
ii  xen-utils-4.0                           4.0.1-4 
 XEN administrative tools
ii  xen-utils-common                        4.0.0-1 
 XEN administrative tools - common files
ii  xenstore-utils                          4.0.1-4 
 Xenstore utilities for Xen
ii  xenwatch                                0.5.4-2 
 Virtualization utilities, mostly for Xen

server2:~# uname -a
Linux server2 2.6.32-5-xen-amd64 #1 SMP Mon Oct 3 07:53:54 UTC 2011 
x86_64 GNU/Linux

And kernel version on domU:

tis:~# uname -a
Linux tis 2.6.32-5-xen-amd64 #1 SMP Mon Oct 3 07:53:54 UTC 2011 x86_64 
GNU/Linux

Could anybody point me to deeper investigation of this strange issue and 
if not - is there any way to get packages of xen-utils-4.0 and 
xenstore-utils before the upgrade to latest version?

Best regards,
--
Peter Viskup