Hello, Wanted to ask, maybe stupid question, maybe somebody can explain me. I installed identical latest Debian 64bit systems on server with E5620 and old test machine with 3040 cpus. On 3040 1.8Ghz cpu Dom0 without VM usage was: Mem: 156528k used, 401388k free After I limited in kernel 500mb aprox. it stayed the same after reboot. In new server with E5620 usage after boot was 1507816k used. After I limited to 1.7Gb aprox: Mem: 1828700k total, 251204k used, 1577496k free, Bouth systems is updated and the same installed with same kernel: 2.6.32-5-xen-amd64 #1 SMP Mon Jan 16 20:48:30 UTC 2012 x86_64 GNU/Linux Why usage of ram is different and after limitation it used less? Thanks, Casper