hello, a big time drift appears along time on a guest VM (time is going too slow on the guest). here the setup: ~ physical machine ~ Centos 6.0 x86_64 time set with ntpd Intel(R) Xeon(R) CPU X5650 /proc/cpuinfo shows the "constant_tsc" bit. ~ guest OS ~ Centos 6.0 x86_64 /proc/cpuinfo : processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 13 model name : QEMU Virtual CPU version (cpu64-rhel6) stepping : 3 cpu MHz : 2666.998 cache size : 4096 KB fpu : yes fpu_exception : yes cpuid level : 4 wp : yes flags : fpu de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pse36 clflush mmx fxsr sse sse2 syscall nx lm up rep_good unfair_spinlock pni cx16 hypervisor lahf_lm bogomips : 5333.99 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual at boot time : [root@xxxx ~]# dmesg | egrep -i 'clock|tsc|time' kvm-clock: Using msrs 12 and 11 kvm-clock: cpu 0, msr 0:18c1901, boot clock ACPI: PM-Timer IO Port: 0xb008 kvm-clock: cpu 0, msr 0:1e16901, primary cpu clock ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 Switching to clocksource kvm-clock uhci_hcd 0000:00:01.2: setting latency timer to 64 rtc_cmos 00:01: setting system clock to 2011-12-15 09:33:28 UTC (1323941608) ata_piix 0000:00:01.1: setting latency timer to 64 Clocksource tsc unstable (delta = -547592984 ns) [root@xxxx ~]# cat /sys/devices/system/clocksource/clocksource0/available_clocksource kvm-clock acpi_pm [root@xxxx ~]# cat /sys/devices/system/clocksource/clocksource0/current_clocksource kvm-clock cpuspeed service is not active on the guest. acpid service is active on the guest (so it can be shut down from the host with "virsh shutdown"). reading Redhat documentation, I did everything ok (that is : guest clocksource set to "kvm-clock" and physical host has a CPU with constant_tsc flag + time set with NTP) : http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/chap-Virtualization_Host_Configuration_and_Guest_Installation_Guide-KVM_guest_timing_management.html is that right ? does anyone have a suggestion about this problem ? thanks Tom _______________________________________________ CentOS-virt mailing list CentOS-virt@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos-virt
