Re: kvm virtualization, consistent guest backup

[Glennie Vignarajah <glennie@glennie.fr>]

Le 15/08/2010 vers 19:48, dans le message intitulé "Re: kvm virtualization, 
consistent guest backup", Martin Kraus(Martin Kraus <lists_mk@wujiman.net>) a 
écrit:


Hello,


> The problem isn't where to backup but how. the problem is to get consistent
> filesystem, consisten data in the filesystem and who know what other
> problems. what I was surprised about is that there is really no
> documentation or usable howto besides how to backup your desktop or small
> bussiness server.

This is a smilar problem for backups used for a disaster recovery procedure.



I use the following policy:
	
	- Apply defined backup policies to every virtual hosts as they were 
*physical* *hosts*. Id est: incremental backup from monday to friday and full 
backup on weekends.

	- The same policy is  applied to the physical host containing 
virtualhosts, but the FS containing virtualhost images are excluded.

	- Every month(or very term), the FS containing virtual machine' images is 
backed up. Of course, the virtual machines are shutdown during the this 
backup!. 	To shudown virtual hosts from a prebackup script, you can use virsh 
or using directly kvm monitor. Have look at 
http://kerneltrap.org/mailarchive/linux-kvm/2010/1/26/6257297/thread. I've 
posted my shutdown script are there is also a simple script for shutting down 
VM using directly KVM/Qemu's socket.

	Of course, you can you use FS snaphosts or KVM snapshosts, but I think 
this is very diffcult to validate FS consitency. 


	And do not forget to *validate* your backups during your tests!

HTH,

-- 
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