Hi,
looking at the qemu-kvm man page, it is possible to enable
snapshot for a given drive. This is what we need because we would like to start a domain
with two drives, one on a file with snapshot=on and an other drive on LVM with
snapshot=off.
Unfortunately it seems that if you use libvirt the same option is not available when you
define the domain with a XML file.
I mean, I didn't find out a way to support the above use case.
So, does libvirt support the drive snapshot option as qemu-kvm does ?
[root@dom0-103-13-26-b libvirt-0.8.8]# cat /etc/issue
Scientific Linux sl54_x86_64
[root@dom0-103-13-26-b libvirt-0.8.8]# rpm -qa | grep libvirt
libvirt-0.6.3-20.1.el5_4.x86_64
libvirt-python-0.6.3-20.1.el5_4.x86_64
[root@dom0-103-13-26-b libvirt-0.8.8]# rpm -qa | grep qemu
qemu-common-0.10.5-1.el5.2.x86_64
kvm-qemu-img-83-164.el5_5.21.x86_64
qemu-system-x86-0.10.5-1.el5.2.x86_64
Below you can find a copy of the XML where we would like to add somewhere the option
snapshot
<domain type='kvm'>
<name>centos5_b</name>
<uuid>a973d1d4-7af6-3f41-a3c1-bea958aba98b</uuid>
<memory>524288</memory>
<currentMemory>524288</currentMemory>
<vcpu>1</vcpu>
<os>
<type arch='x86_64' machine='rhel5.4.0'>hvm</type>
<boot dev='hd'/>
</os>
<features>
<acpi/>
<apic/>
<pae/>
</features>
<clock offset='utc'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<devices>
<emulator>/usr/libexec/qemu-kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' cache='none'/>
<source file='/home/davide/WNoDeS/disks/centos5_b.raw'/>
<target dev='vda' bus='virtio'>
</disk>
<disk type=block device='disk'>
<source file='/dev/vg0/lv_slash'/>
<target dev='vda' bus='virtio'>
</disk>
<disk type='file' device='cdrom'>
<target dev='hdc' bus='ide'/>
<readonly/>
</disk>
<interface type='bridge'>
<mac address='00:16:36:36:70:3e'/>
<source bridge='br0'/>
<model type='virtio'/>
</interface>
<serial type='pty'>
<target port='0'/>
</serial>
<console type='pty'>
<target port='0'/>
</console>
<input type='mouse' bus='ps2'/>
<graphics type='vnc' port='-1' autoport='yes'
keymap='it'/>
</devices>
</domain>
Thanks in advance
Alessanndro
**********************************************
Alessandro Italiano
INFN-CNAF,Tier1 Farming Group
Viale Berti Pichat 6/2, 40127 Bologna, Italy
Tel: +39 051 6092751
alessandro.italiano(a)cnaf.infn.it
www.cnaf.infn.it
Skype#alessandroitaliano
**********************************************