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Matt
Asked: 2014-10-16 10:14:05 +0800 CST

libvirt / kvm guests take very long time to start after host reboot

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Host system is CentOS 6.5 x86_64. I have setup an Ubuntu guest by following this wiki. The guest works, but: if I reboot the host, it takes a very long time (about 30 minutes on the last reboot) before the guests actually start. If, during this time, I start virsh and do a "list", it just hangs.

Here's a snippet from /var/log/libvirt/libvirt.log:

2014-10-14 16:47:11.509+0000: 4668: info : virDomainLoadAllConfigs:14696 : Scanning for configs in /var/run/libvirt/qemu
2014-10-14 16:47:11.527+0000: 4668: info : virDomainLoadAllConfigs:14696 : Scanning for configs in /etc/libvirt/qemu
2014-10-14 16:47:11.527+0000: 4668: info : virDomainLoadAllConfigs:14718 : Loading config file 'mythbuntu.xml'
2014-10-14 16:47:11.529+0000: 4668: info : qemuDomainSnapshotLoad:484 : Scanning for snapshots for domain mythbuntu in /var/lib/libvirt/qemu/snapshot/mythbuntu
2014-10-14 17:14:41.751+0000: 4668: info : virNetDevProbeVnetHdr:94 : Enabling IFF_VNET_HDR
2014-10-14 17:14:41.805+0000: 4668: info : virSecurityDACSetOwnership:296 : Setting DAC user and group on '/home/kvm/mythbuntu.img' to '107:107'
2014-10-14 17:14:41.806+0000: 4668: info : virSecurityDACSetOwnership:296 : Setting DAC user and group on '/mnt/mythtv1/mythbackend_recordings' to '107:107'
2014-10-14 17:14:42.084+0000: 4668: info : lxcSecurityInit:1380 : lxcSecurityInit (null)

Notice that huge jump in time, from 16:47:11 to 17:14:41? The latter time is when the guest actually started, and at this point, "virsh list" was once again usable.

It seems like libvirt/kvm/qemu is getting hung up on something, but eventually is able to proceed. Anyone have any idea what it might be hung up on?

Edit: I am not using snapshots. And in fact:

# ls /var/lib/libvirt/qemu/snapshot/mythbuntu
ls: cannot access /var/lib/libvirt/qemu/snapshot/mythbuntu: No such file or directory

The parent looks like this:

# ls -R /var/lib/libvirt/qemu/
/var/lib/libvirt/qemu/:
dump  mythbuntu.monitor  save  snapshot

/var/lib/libvirt/qemu/dump:

/var/lib/libvirt/qemu/save:

/var/lib/libvirt/qemu/snapshot:
centos

0 Answers