I am running Xen 4.0.1 on debian squeeze. I have 2 Win2008R2 HVMs running on it. Dom0 is using NTPDate and has a solid time. Zero problem with Dom0. Now, the strange part. One vm''s clock drifts, while the other vm''s clock does not drift. Of course I do use NTP as both are part of a windows domain, so ultimately W32TM does correct the issue (or keeps it within the domain tolerance). The .CFGs are identical except for the ram/disks and... VCPUs OK, HVM configs. These settings are common in both the VM that drifts and the one that does not. acpi = 1 apic = 1 device_model = ''/usr/lib/xen-4.0/bin/qemu-dm'' boot="c" localtime=1 sdl=0 serial=''pty'' timer_mode=2 viridian=1 Now for the Differences.... ********** Does not Drift ********** builder=''hvm'' memory = 16384 shadow_memory = 96 vcpus=6 cpus="8-15" ************************************** ********** Drifts ********** builder=''hvm'' memory = 8096 shadow_memory = 30 cpus="4-5" vcpus=2 **************************** Below is a /stripchart from W32TM in the one that drifts. 16:39:02 d:+00.0625636s o:+03.8884581s [ | * ] 16:39:33 d:+00.0625636s o:+03.9052416s [ | * ] 16:40:03 d:+00.0624592s o:+03.9651983s [ | * ] 16:40:33 d:+00.0624592s o:+04.1260910s [ | * ] 16:41:03 d:+00.0624592s o:+04.3182343s [ | * ] 16:41:33 d:+00.0780740s o:+04.7369497s [ | * ] 16:42:03 d:+00.0624592s o:+04.9525362s [ | * ] 16:42:33 d:+00.0624592s o:+05.3478084s [ | * ] 16:43:04 d:+00.0624592s o:+05.7430806s [ | * ] 16:43:34 d:+00.0624592s o:+06.1071022s [ | * ] 16:44:04 d:+00.0624592s o:+06.7836298s [ | * ] 16:44:34 d:+00.0624592s o:+07.0382848s [ | * ] 16:45:04 d:+00.0624216s o:+07.2666513s [ | * ] 16:45:34 d:+00.0624216s o:+07.6019390s [ | * ] 16:46:04 d:+00.0624216s o:+08.1559809s [ | * ] 16:46:34 d:+00.0624216s o:+08.5850204s [ | * ] 16:47:05 d:+00.0637092s o:+08.6929941s [ | * ] I have two identical servers, running these same HVMs, and both do the same exact thing. Both servers are Supermicro''s with dual Xeon L5630 CPUs and 64gig of ram. I can''t help but think that the VCPUs has something to do with this... I really can''t try upping the VCPUs as these are running in production/dr environments. Any ideas? Thanks :-) Tod _______________________________________________ Xen-users mailing list Xen-users@lists.xen.org http://lists.xen.org/xen-users