[CentOS] CentOS 6 P2V alternatives?

[hw]

Robert Nichols wrote:
> On 11/03/2017 06:09 AM, hw wrote:
>> Sorin Srbu wrote:
>>> Hello all,
>>>
>>> This week I've tested out a few ways to do a P2V on a rather ancient CentOS
>>> 6 server, in order to move it to a Hyper-V host.
>>>
>>> So far my tests have failed rather spectacularly.
>>> Initially I was set on doing a simple dd-routine, but was told that the
>>> server cannot be taken off-line as it's being used daily, so had to look for
>>> other solutions.
>>>
>>> The disk setup is currently as follows:
>>>
>>> Three 500 GB sata-disks, sda, sdb and sdc, are used to build a software raid
>>> called md0. No LVM's here.
>>>
>>> Sdd is a 120 GB drive, with partitions for boot, swap, home and /.
>>> No LVM's here either.
>>>
>>> The farthest I've gotten is with the Rear solution.
>>> http://relax-and-recover.org/
>>>
>>> The backup goes well, but recovery for some reason fails to create initramfs
>>> with all the installed kernels, as well as failing with an error saying it
>>> cannot find /boot/grub, after which the recovery terminates.
>>>
>>> Virtualizing systems like this is kinda' new to me, having it done on
>>> Windows only, and I'm not really sure
>>> how to proceed when it's a CentOS system in question.
>>>
>>> The physical CentOS-server runs a few license managers and nfs-shares that
>>> server molecular modeling software, that are rather intricately set up (I
>>> inherited this server some fifteen years ago).
>>>
>>> Are there any easier ways to do a P2V at all?
>>>
>>
>> I think I would try to create a VM that has the physical disks passed through
>> and also has access to whatever storage it´s supposed to reside on once the
>> conversion to a VM is completed.  Then copy it from the physical disks to that
>> storage.
>>
>> Converting without shutting the machine down is probably not possible.
>
> How would you recover if that server were suddenly destroyed, let's say by a power supply failure that fried the motherboard and all the disks? If you can't bring up a machine on new, bare iron starting with nothing but your backups and a CD or USB stick with a recovery tool, you need to seriously reconsider your backup strategy.

That´s a very good point.

What options are there to make complete and consistent backups of machines
and VMs while they are running?  Just shutting down a VM to make a backup
is troublesome because you sometimes need to run 'virsh shutdown xx' several
times for the VM to actually shut down, and I have VMs that do not shut down
no matter how often you try.  If you manage to shut down the VM, there is no
guarantee that it will actually restart when you try --- and that goes for
non-VMs as well.  Shutting them down manually frequently to make backups is
not an option, either.