Bug 727709 - Cannot take snapshots with virsh snapshot-create: The command savevm has not been found
Summary: Cannot take snapshots with virsh snapshot-create: The command savevm has not ...
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: libvirt
Version: 15
Hardware: x86_64
OS: Linux
unspecified
high
Target Milestone: ---
Assignee: Libvirt Maintainers
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-08-02 23:59 UTC by Andrew Bartlett
Modified: 2012-06-07 00:48 UTC (History)
14 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
: 733499 (view as bug list)
Environment:
Last Closed: 2012-06-07 00:48:54 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Andrew Bartlett 2011-08-02 23:59:55 UTC
Description of problem:
Running virsh snapshot-create <domain> fails

Version-Release number of selected component (if applicable):
libvirt-0.8.8-7.fc15.x86_64
qemu-kvm-0.14.0-7.fc15.x86_64

How reproducible:
Every time

Steps to Reproduce:
1. Install virtual machine (Windows 2008R2 in this case) with qcow2 disk
2. Start the VM
3. sudo virsh snapshot-create Win2008R2-5
4. sudo virsh snapshot-list Win2008R2-5

  
Actual results:
sudo virsh snapshot-create Win2008R2-5
error: internal error unable to execute QEMU command 'savevm': The command savevm has not been found

[abartlet@obed samba-1]$ sudo virsh snapshot-list Win2008R2-5
 Name                 Creation Time             State
---------------------------------------------------
 1312291332           2011-08-02 23:22:12 +1000 shutoff
 1312328890           2011-08-03 09:48:10 +1000 nostate

Expected results:
The creation of a running snapshot

Additional info:

This did work in Fedora 14.  It fails for all the VMs I've tried. 

This snapshot mechanism was being used to support Samba development via Wintest:
http://blog.tridgell.net/?p=91

Comment 1 Richard Harman 2011-08-12 12:30:20 UTC
I think this is a result of libvirt communicating with qemu via the new json interface, the savevm command -is- present in qemu, just not through json.

Comment 2 Eric Blake 2011-08-12 15:54:49 UTC
Ouch - libvirt should have detected the monitor failure, rather than proceeding to create a bogus metadata entry.  I'll take a further look into this today.

Comment 3 Richard Harman 2011-08-12 17:43:26 UTC
BTW - it looks like there is a work-around in the libvirtd package in rawhide, it falls back to the previous way of communicating with QEMU instead of the JSON stuff.

Think that individual change could be back ported to F15?

Comment 4 Eric Blake 2011-08-12 21:02:01 UTC
There's two bugs here:

1. libvirt not attempting qmp->hmp fallback with qemu that doesn't support qmp savevm (upstream commit 89241fe0, v0.9.0, although several other related commits would also have to be backported; at least: 266265a, 89241fe, ce81bc5, abdfca0, 24c56ce, c33ac2e, 0ecfa7f)

2. On savevm failure, libvirt leaks bogus metadata into snapshot lists even when snapshot creation fails (just posted the upstream fix for that):
https://www.redhat.com/archives/libvir-list/2011-August/msg00531.html

F15 (at libvirt 0.8.8) is affected by both problems; F16 is immune to the first, and the second is less likely to hit.  I'm not sure if F14 also has an issue.

If you are impatient, you can use the virt-preview repo to pick up the libvirt build from F16 compiled for F15, which will solve the first bug, and probably get you to the point of not tickling the second bug.

And there's lots more active work going on for snapshots for upstream 0.9.5, you could always help test libvirt.git.

Comment 5 Eric Blake 2011-08-12 21:07:53 UTC
I've checked F14; this is a regression (F14 at 0.8.3 predated the switch to use qmp by default, so it was using snapshots on hmp), so it is definitely a candidate for fixing for F15.

Comment 6 Fedora Admin XMLRPC Client 2011-09-22 17:54:19 UTC
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 7 Fedora Admin XMLRPC Client 2011-09-22 17:58:17 UTC
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 8 David Busby 2011-11-01 14:00:03 UTC
This bug also present on el6.

package versions.

libvirt-0.8.1-27.el6_0.6.x86_64
qemu-kvm-0.12.1.2-2.113.el6_0.8.x86_64

Comment 9 Fedora Admin XMLRPC Client 2011-11-30 20:05:28 UTC
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 10 Fedora Admin XMLRPC Client 2011-11-30 20:05:40 UTC
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 11 Fedora Admin XMLRPC Client 2011-11-30 20:09:16 UTC
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 12 Fedora Admin XMLRPC Client 2011-11-30 20:09:35 UTC
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 13 Cole Robinson 2012-06-07 00:48:54 UTC
Given that F15 is end of life very soon, and the number of backports we would probably need as mentioned in Comment #4, I think this is WONTFIX for F15. If anyone can still reproduce on later Fedora, please reopen and we can go from there.


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