Red Hat Bugzilla – Bug 578734
Time sync issues on RHEL4.8 and RHEL 5.4 guests
Last modified: 2013-07-02 03:12:12 EDT
Description of problem:
We've been using RHEL4.8 (2.6.9-89.ELsmp) KVM guests for a bit, and moved over several more from Xen to KVM last week (our buildfarm guests). All of our RHEL4.8 guests have been reporting this for some time:
Same confirmed using RHEL5.4 guests.
warning: many lost ticks.
Your time source seems to be instable or some driver is hogging interupts
However this hadn't been impacting us. On our buildfarm systems, however, clock drift is a problem for the RHEL4 64-bit guests (not for RHEL3 32-bit and 64-bit guests using virtio drivers).
Version-Release number of selected component (if applicable):
Steps to Reproduce:
Monitor clock with ntptime, here's sample output:
[root@bf10 ~]$ ntptime
ntp_gettime() returns code 5 (ERROR)
time ced1122e.dffe4000 Mon, Dec 14 2009 11:36:14.874, (.874973),
maximum error 16384000 us, estimated error 16384000 us
ntp_adjtime() returns code 5 (ERROR)
modes 0x0 (),
offset 0.000 us, frequency 0.000 ppm, interval 4 s,
maximum error 16384000 us, estimated error 16384000 us,
status 0x41 (PLL,UNSYNC),
time constant 0, precision 1.000 us, tolerance 512 ppm,
pps frequency 0.000 ppm, stability 512.000 ppm, jitter 200.000 us,
intervals 0, jitter exceeded 0, stability exceeded 0, errors 0.
During migration between different hosts, the time sync fails
No time sync issues.
I'll find out the cmd line. The kernel options used are as described in http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5.4/html/Virtualization_Guide/chap-Virtualization-KVM_guest_timing_management.html
Change bug title to make more sense; this has nothing to do with migration between hosts with different CPU speeds.
What exactly do you mean by relative package?
*** This bug has been marked as a duplicate of bug 531701 ***