Bug 742736
| Summary: | Use rtc tickpolicy catchup by default for windows guests | ||||||
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| Product: | Red Hat Enterprise Linux 6 | Reporter: | Dor Laor <dlaor> | ||||
| Component: | python-virtinst | Assignee: | Cole Robinson <crobinso> | ||||
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> | ||||
| Severity: | high | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 6.2 | CC: | acathrow, berrange, hjiang, mjenner, mzhan, rwu, syeghiay, tburke, uobergfe, zpeng | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | Unspecified | ||||||
| OS: | Unspecified | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: |
Cause:
virt-install was not specifying any clock policy for windows guests.
Consequence:
windows guest time would skew from host time
Fix:
virt-install specifies the tickpolicy 'catchup' for windows guests.
Result:
windows guest time is less likely to skew
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Story Points: | --- | ||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2011-12-06 16:17:27 UTC | Type: | --- | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Bug Depends On: | |||||||
| Bug Blocks: | 748554 | ||||||
| Attachments: |
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Description
Dor Laor
2011-10-02 09:34:11 UTC
According to Daniel we should have this:
<clock offset="localtime">
<timer name="rtc" tickpolicy="catchup">
</clock>
It's fine to do it for all guests. Old rhel5 hypervisor info (which is still valid w/ interface changes): http://cleo.tlv.redhat.com/qumrawiki/KVM/TimeKeeping Again I have to ask, if it's fine to do it for all guests, why isn't this the default at the qemu level? Specifically what OS need this to behave properly? Just WinXP? All windows (even win7)? (In reply to comment #3) > Again I have to ask, if it's fine to do it for all guests, why isn't this the > default at the qemu level? It shouldn't be set for all the guests but for most, nothing bad will happen if it exists (apart from rhel3). That's why we don't do it blindly w/ qemu (in addition to ignorant upstream qemu community w.r.t non x86) > > Specifically what OS need this to behave properly? Just WinXP? All windows > (even win7)? All windows flavors Created attachment 528826 [details]
Use clock timer mode 'catchup' for windows guests
Not a proper fix for upstream inclusion since that requires a bit more code than is worth backporting, but this should solve our issues for RHEL6.
Fixed in python-virtinst-0.600.0-5.el6 Reproduced with the following package: python-virtinst-0.600.0-3.el6.noarch Verified with kernel-2.6.32-197.el6.x86_64 qemu-kvm-0.12.1.2-2.192.el6.x86_64 libvirt-0.9.4-19.el6.x86_64 python-virtinst-0.600.0-5.el6.noarch virt-manager-0.9.0-7.el6.x86_64 step: 1. Download a window2008 image from http://fileshare.englab.nay.redhat.com/pub/section3/libvirtmanual/Windows_KVM_images/win2008r2-64.qcow2 2. #virt-manager 3. Create a new guest w08 use the above image with the following steps: Create a new guest-> name is w08;import existing disk image -> select the downloaded win2008 image; os is windows; versions is microsoft windows server 2008;-> Leave other configure default. 4. Run the guest, log into the guest ,found time is almost same with host. 5. use command #iozone -a to create load on host, and found guest's time is also almost same with host. 6. #virsh dumpxml w08 ... <clock offset='localtime'> <timer name='rtc' tickpolicy='catchup'/> </clock> ... 7. # ps -aef | grep qemu qemu 22784 1 7 18:05 ? 00:01:38 /usr/libexec/qemu-kvm -S -M rhel6.2.0 -enable-kvm -m 1024 -smp 1,sockets=1,cores=1,threads=1 -name xp -uuid ffafeb4c-df29-01c5-1e7e-78f58dbc2759 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/xp.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=localtime,driftfix=slew -no-shutdown -drive file=/var/lib/libvirt/images/xp.img,if=none,id=drive-ide0-0-0,format=raw,cache=none -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -netdev tap,fd=23,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=52:54:00:3c:b2:ef,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -device usb-tablet,id=input0 -vnc 127.0.0.1:0 -vga std -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 8. Check other windows guest; such as xp, win03, win7. All of them are OK So move the status of this bug to 'verified'.
Technical note added. If any revisions are required, please edit the "Technical Notes" field
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New Contents:
Cause:
virt-install was not specifying any clock policy for windows guests.
Consequence:
windows guest time would skew from host time
Fix:
virt-install specifies the tickpolicy 'catchup' for windows guests.
Result:
windows guest time is less likely to skew
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2011-1643.html *** Bug 767188 has been marked as a duplicate of this bug. *** |