recovery of virtual machines on KVM

[Tapas Mishra]

On Thu, Feb 10, 2011 at 1:40 PM, Alvin <info at alvin.be> wrote:
> On Wednesday 09 February 2011 19:39:57 Tapas Mishra wrote:
>> I  am having a virtualization setup via KVM on a Ubuntu 10.04 64 bit
>> server.
>>
>> A recent dbus update cause a crash of my Host OS.It was a post install
>> script of dbus which ultimately brought everything down.
>>
>> Now I have to basically format the host OS.My cause of concern are the
>> virtual machines which were running on it when the environment was
>> stable.Which were in separate LVM partitions.
>>
>> Some thing like
>>
>> /dev/virtualization/vm1
>> /dev/virtualization/vm2
>> /dev/virtualization/vm3
>> /dev/virtualization/vm4
>> If some one has experienced recovery of this sort in past let me know
>> what did they do to get things back. All my Virtual Machines were on
>> separate partition and in same VolumeGroup this volume group was on
>> Host OS. Will formatting of HOST os clear the Virtual Machines also in
>> my situation or just be re installing the host and importing the
>> Virtual Machines via a tool such as virt-manager I will be able to get
>> them back.
>
> Before your reinstall, dump the configuration of your virtual machines like
> this:
> $ virsh dumpxml vm1 > vm1.xml
> After reinstall, redefine the machines
> $ virsh define vm1.xml
>
> It's that simple, but of course you have to leave your LVM volumes in place
> and make sure your host has the same network interfaces (as defined in the
> xml).
>
Not possible because the host OS where I was getting this problem I
was not even able to login.
So what I did is a fresh install and copied the xml files from a
backup I had on a USB is that not the correct way to do?
I just noticed I am unable to connect to guest OS after this i.e. when
the host OS reboots and then I immedialtely do an SSH to the guest
from any machine within my network I am able to do so but after 5-10
minutes if I again do an ssh to the same guest then I get host not
found error.