Re: [Qemu-stable] Building from source

[Michael Roth]

Quoting Joshua Cannell (2015-02-18 13:12:19)
> Hello,
> 
> I'm having some issues using libvirt snapshots after building QEMU from 
> source.
> I'm not sure if this is the right area to post these questions but I guess 
> I'll
> find out.
> 
> I using QEMU 2.2.0.
> I need to compile QEMU from source because there slight changes I need to make
> to the source. However, I can't seem to get snapshots working even if I don't
> change anything.
> 
> I can configure, make, and install a completely unmodified QEMU from source
> just fine. However, I can't successfully revert to snapshots created for my 
> VMs
> using virsh or virt-manager.
> 
> Here is how I'm compiling it:
> ./configure --prefix=/usr
> make
> sudo checkinstall
> 
> I just call the package qemu 2.2.0 and it's built and installed.
> 
> When I open my VM in virt-manager, I take a snapshot. However, when I try
> revertting I get:
> 
> Error running snapshot 'base': operation failed: Error -22 while loading VM
> state
> 
> Traceback (most recent call last):
>   File "/home/josh/virt-manager/virtManager/asyncjob.py", line 89, in
> cb_wrapper
>     callback(asyncjob, *args, **kwargs)
>   File "/home/josh/virt-manager/virtManager/asyncjob.py", line 125, in tmpcb
>     callback(*args, **kwargs)
>   File "/home/josh/virt-manager/virtManager/domain.py", line 1039, in
> revert_to_snapshot
>     self._backend.revertToSnapshot(snap.get_backend())
>   File "/usr/lib/python2.7/dist-packages/libvirt.py", line 1796, in
> revertToSnapshot
>     if ret == -1: raise libvirtError ('virDomainRevertToSnapshot() failed', 
> dom
> =self)
> libvirtError: operation failed: Error -22 while loading VM state
> 
> The domain is paused. When I resume it, it displays the Windows Error Recovery
> screen.
> I tried the same thing creating a snapshot with virsh, same error.
> If I first shutdown the VM, and then revert to the snapshot, it goes straight
> to the Error console again.
> 
> Here is my virsh version info:
> Compiled against library: libvirt 1.2.2
> Using library: libvirt 1.2.2
> Using API: QEMU 1.2.2
> Running hypervisor: QEMU 2.2.0
> 
> Whenever I install QEMU from the repos, everything works fine, but I need to
> build it from source for a project I'm working on so that's not an option.
> However, when I use the QEMU install I built from source, everything else 
> seems
> to work fine, except for snapshots.
> 
> Any help would be really, really appreciated.

This list is actually for collecting new/upstream fixes for stable release
updates to older QEMU releases. Anything involving new/standing bugs should
go to the development list: address@hidden

I would re-submit your query there. But one thing you might want to double-check
is that you're explicitly specifying the same machine-type (-M or -machine
option if you were running QEMU directly) when using the compiled version of
QEMU 2.2. Otherwise it will default to a newer machine type, which can cause
issues for guests that were previously using an older machine type.

> 
> --
> -Josh