Backup Strategies for Virtual Machines

[ArnoldAardvark]

I am proposing having a server built at work which will be virtualised
to contain 2 virtual SQL servers, a production and development server.
Arcserve is the backup software in use at our site and I would like to
find out more about the backup strategies people are employing for
virtual SQL servers.

In particular are they just using open file backup of the VMs or
individual database backups within each VM or a combination of both.

I am also interested in finding out how Arcserve is installed in these
situations i.e. what components are installed on the real server and
what on the virtual server.

Any help would be appreciated as our systems team have no idea and I am
fairly new to all this.

Many thanks

Arnold

[Alessandro Perilli [GMail]]

Arnold,
the best option in my opinion is act at host level instead of guest level.

This approach has the downside of long restore time and is strictly
dependend on which virtualization platform you are using.

Could you provide this information?

Alessandro

Alessandro Perilli, CISSP, MVP
IT Security and Virtualization Technology Analyst
http://www.alessandroperilli.com

LinkedIn: https://www.linkedin.com/in/alessandroperilli

Blogging about IT Security on http://www.securityzero.com Blogging about
Virtualization on http://www.virtualization.info

[ArnoldAardvark]

Hi Alessandro,
I am proposing using VMWare server for this. Ideally we should use
VMWare ESX server but having no other ESX servers, I think (though I
could be mistaken) this would be a problem with disaster recovery if we
needed to restore the VMs, since ESX uses its own Linux based file
system.

The site I am working at does not currently employ virtualisation,
although on our project we have cobbled together a server and created 3
virtual servers for development purposes.

The simplest solution currently, and least problematic for the systems
team, may be to treat each VM as a physical server and back it up as
currently to the tape drive attached to the physical server. In this
scenario I am not sure whether I would need to install Arcserve on the
host machine and the SQL and File agents on each VM, or a complete set
of client and agent software on each VM.

If I back up each VM, which as I understand it, needs to be done by
stopping or temporarily pausing each VM when using VMWare Server, prior
to the backup then the process of restoring a database or table
involves having to restore the whole VM to another server or new VM.

Thanks
Arnold

[Alessandro Perilli [GMail]]

Arnold,
I have some strong experience with VMs live backup on VMware GSX Server on
Windows host.

While the existance of Windows Volume Shadow Service (VSS) allows to live
backup any locked file (including .vmdk and .vmx) Microsoft has a bug (or at
least they are saying it's a bug) on its NTBackup.
This prevents NTBackup to use VSS for backing up open files larger than 2GB
(you won't find any documentation on this around).

Luckily 3rd parties backup solutions use VSS in a more reliable way and can
be used to achieve VMware VM live backup.
In the past I spent many days comparing competing solutions on the market
and found CA ArcServe the most flexible, fast and reliable for this task.

But even if CA ArcServe is able to successfully perform the live backup,
this operation is not officially supported by VMware, becuase its products
are not VSS aware at the moment.

I personally found no restoring problems (eg: file system inconsistencies)
in the last 3 years adopting this method for several kind of virtual
machines, including Microsoft Exchange 2003 and SQL Server 2000/2005.

A new approach to perform VMware (GSX) Server VMs live backup, still using
the Windows 2003 VSS feature, is the one offered by Double Take.

Double Take leverages the new so-called continous data protection (CDP) to
live backup VMs, only replicating portion of files (in this case .vmdk)
which changed over time.

VMware endorsed the solution in many occasions, with joined whitepapers and
webacsts, even if, AKAIF, they never officially stated Double Take approach
is supported to live backup VMs on a Windows host.

Hope this can help.
Alessandro

Alessandro Perilli, CISSP, MVP
IT Security and Virtualization Technology Analyst
http://www.alessandroperilli.com

LinkedIn: https://www.linkedin.com/in/alessandroperilli

Blogging about IT Security on http://www.securityzero.com
Blogging about Virtualization on http://www.virtualization.info

-----Original Message-----
From: virtualiz...@googlegroups.com
[mailto:virtualiz...@googlegroups.com] On Behalf Of ArnoldAardvark
Sent: venerdì 13 ottobre 2006 11.09
To: virtualization.info Discussion Group