Hello, I have clock synchronization problems with Fedora 18/KVM host and windows server guests. Different 64bit windows servers, all has some time synchronization problems. Some of them will slow down time until time difference is 60 seconds and then clock is synchronizes from internet. But 60 seconds is a long time. Kerberos authentication sometimes files due to time skew. Some machines will run OK day or two, but then clock stops. After some hours clock is synchronized again and continues to work properly. Curious, that during time is stopped, server works properly (except kerberos authentications, which is very time sensitive. For example, attaching 2 graphs from 2 windows servers. They show time difference measured by check_mk nagios plugin. 10k means 10000 seconds. How I should set clock/time/NTP on these guests? I have absolutelly no problems with Linux guests, they work perfectly.

On Tue, Jun 25, 2013 at 3:01 PM, Cole Robinson <crobinso(a)redhat.com&gt; wrote: > On 06/24/2013 02:18 PM, Ján ONDREJ (SAL) wrote: > Maybe try altering the guest config with: > > <clock offset='utc'> > <timer name='pit' tickpolicy='delay'/> > <timer name='rtc' tickpolicy='catchup'/> > </clock>

> https://bugs.launchpad.net/nova/+bug/1011848 > https://bugzilla.redhat.com/show_bug.cgi?id=828332 > > virt-manager/virt-install should be doing this by default.

Have you checked the clock of the hypervisor the guest is running on?

On 06/24/2013 02:18 PM, Ján ONDREJ (SAL) wrote: > Hello, > > I have clock synchronization problems with Fedora 18/KVM host and windows > server guests. Different 64bit windows servers, all has some time > synchronization problems. > > Some of them will slow down time until time difference is 60 seconds and > then clock is synchronizes from internet. But 60 seconds is a long time. > Kerberos authentication sometimes files due to time skew. > > Some machines will run OK day or two, but then clock stops. After some > hours clock is synchronized again and continues to work properly. > Curious, that during time is stopped, server works properly (except kerberos > authentications, which is very time sensitive. > > For example, attaching 2 graphs from 2 windows servers. They show time > difference measured by check_mk nagios plugin. 10k means 10000 seconds. > > How I should set clock/time/NTP on these guests? > > I have absolutelly no problems with Linux guests, they work perfectly. > Maybe try altering the guest config with: <clock offset='utc'> <timer name='pit' tickpolicy='delay'/> <timer name='rtc' tickpolicy='catchup'/> </clock> https://bugs.launchpad.net/nova/+bug/1011848 https://bugzilla.redhat.com/show_bug.cgi?id=828332 virt-manager/virt-install should be doing this by default.

> Any ideas? Is this a bug? > Possibly, please file a Fedora qemu bug and list all the info you've given here.

On 07/03/2013 01:54 AM, "Ján ONDREJ (SAL)" wrote: > Hello, > > On Tue, Jun 25, 2013 at 03:01:15PM -0400, Cole Robinson wrote: >> On 06/24/2013 02:18 PM, Ján ONDREJ (SAL) wrote: >>> Hello, >>> >>> I have clock synchronization problems with Fedora 18/KVM host and windows >>> server guests. Different 64bit windows servers, all has some time >>> synchronization problems. >>> >>> Some of them will slow down time until time difference is 60 seconds and >>> then clock is synchronizes from internet. But 60 seconds is a long time. >>> Kerberos authentication sometimes files due to time skew. >>> >>> Some machines will run OK day or two, but then clock stops. After some >>> hours clock is synchronized again and continues to work properly. >>> Curious, that during time is stopped, server works properly (except kerberos >>> authentications, which is very time sensitive. >>> >>> For example, attaching 2 graphs from 2 windows servers. They show time >>> difference measured by check_mk nagios plugin. 10k means 10000 seconds. >>> >>> How I should set clock/time/NTP on these guests? >>> >>> I have absolutelly no problems with Linux guests, they work perfectly. >>> >> >> Maybe try altering the guest config with: >> >> <clock offset='utc'> >> <timer name='pit' tickpolicy='delay'/> >> <timer name='rtc' tickpolicy='catchup'/> >> </clock> >> >> https://bugs.launchpad.net/nova/+bug/1011848 >> https://bugzilla.redhat.com/show_bug.cgi?id=828332 >> >> virt-manager/virt-install should be doing this by default. > > These didn't helped me to fix my problem. Also trying combinations > of these without success: > > <clock offset='variable' adjustment='2' basis='utc'> > <timer name='rtc' tickpolicy='catchup'/> > <timer name='pit' tickpolicy='delay'/> > <timer name='hpet' present='yes'/> > </clock> > <qemu:commandline> > <qemu:arg value='-rtc-td-hack'/> > </qemu:commandline> > > Any ideas? Is this a bug? > Possibly, please file a Fedora qemu bug and list all the info you've given here.

On 07/04/2013 02:03 AM, "Ján ONDREJ (SAL)" wrote: > Hello, > > On Wed, Jul 03, 2013 at 11:08:48AM -0400, Cole Robinson wrote: >> On 07/03/2013 01:54 AM, "Ján ONDREJ (SAL)" wrote: >>> Hello, >>> >>> On Tue, Jun 25, 2013 at 03:01:15PM -0400, Cole Robinson wrote: >>>> On 06/24/2013 02:18 PM, Ján ONDREJ (SAL) wrote: >>>>> Hello, >>>>> >>>>> I have clock synchronization problems with Fedora 18/KVM host and windows >>>>> server guests. Different 64bit windows servers, all has some time >>>>> synchronization problems. >>>>> >>>>> Some of them will slow down time until time difference is 60 seconds and >>>>> then clock is synchronizes from internet. But 60 seconds is a long time. >>>>> Kerberos authentication sometimes files due to time skew. >>>>> >>>>> Some machines will run OK day or two, but then clock stops. After some >>>>> hours clock is synchronized again and continues to work properly. >>>>> Curious, that during time is stopped, server works properly (except kerberos >>>>> authentications, which is very time sensitive. >>>>> >>>>> For example, attaching 2 graphs from 2 windows servers. They show time >>>>> difference measured by check_mk nagios plugin. 10k means 10000 seconds. >>>>> >>>>> How I should set clock/time/NTP on these guests? >>>>> >>>>> I have absolutelly no problems with Linux guests, they work perfectly. >>>>> >>>> >>>> Maybe try altering the guest config with: >>>> >>>> <clock offset='utc'> >>>> <timer name='pit' tickpolicy='delay'/> >>>> <timer name='rtc' tickpolicy='catchup'/> >>>> </clock> >>>> >>>> https://bugs.launchpad.net/nova/+bug/1011848 >>>> https://bugzilla.redhat.com/show_bug.cgi?id=828332 >>>> >>>> virt-manager/virt-install should be doing this by default. >>> >>> These didn't helped me to fix my problem. Also trying combinations >>> of these without success: >>> >>> <clock offset='variable' adjustment='2' basis='utc'> >>> <timer name='rtc' tickpolicy='catchup'/> >>> <timer name='pit' tickpolicy='delay'/> >>> <timer name='hpet' present='yes'/> >>> </clock> >>> <qemu:commandline> >>> <qemu:arg value='-rtc-td-hack'/> >>> </qemu:commandline> >>> >>> Any ideas? Is this a bug? >>> >> >> Possibly, please file a Fedora qemu bug and list all the info you've given here. > > Looks like there are 2 different clock problems and looks like I can > identify, when they appear. > > I have 2 types of machines, 1st with virtio drivers and 2nd without virtio > drivers (default hardware configurations). > > 1st type - virtio drivers installed, version virtio-win-0.1-59.iso (or 52) > - clock sometimes stops working completelly. I see more hours same time > on machine. > - screenshot image-virtio.png attached > > 2nd type - IDE disk and default network (e1000?) > - clock skew is 0-80 seconds. It's better like for 1st type. > - screenshot image-novirtio.png attached > > Looks like there are some problems with virtio drivers, which stops > clock. Now I will try, if I can avoid problems with only one virtio driver > (net or disk). > > Are ther commercial customers using these drivers? > Also have problems? Best way to get some response for these questions is to file a separate bug against the virtio-win component in Fedora, where all the virtio-win guys are watching.