Networker

Re: [Networker] backing up vmware (esx3) from Legato, guests, hosts, does it work best practices?

2007-04-02 23:27:50
Subject: Re: [Networker] backing up vmware (esx3) from Legato, guests, hosts, does it work best practices?
From: Rodney Rutherford <rrutherf AT tripos DOT com>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Mon, 2 Apr 2007 22:23:03 -0500
Regarding the scripts, see http://www.vmts.net/

There you will find the vmbk script which works great
on version 2.x of VMware.  Note that you will need a large
disk staging area to write the backups to, then you back that
up to tape.

Another thing to note regarding the vmbk script.  He currently
has direct support for NetBackup but not NetWorker.  It might
be trivial to incorporate direct support for NetWorker, or
too possibly use it with savepnpc to limit the amount of disk
needed for staging.

Taking a new look at that page, I see that he also has a new
3.x version of the vmbk script for use with ESX 3.x.

As for VMware Consolidated Backup (VCB -- that is what the VMware
sales/marketing were referring to), it "sort of" works.  It is
really more for disaster recovery, since you are backing up the
actual virtual disk and vm configs of the guests only.

If you want incremental data from the running VM guest, you really
need to use a NetWorker client installed directly on the guest (just
like a normal physical host), and that is actually what VMware
recommends for backup of "application data"  (though VCB can do
file-level backups of Windows guests only).  Full VCB backups are
really recommended for DR and system images.

Otherwise, if all you are doing is VCB full guest backups, the answer
for incremental file level restores in the guest is to recover
the VCB data to disk, then import it into a new guest,  then manually
recover the desired files to the existing guest.  Not exactly a
streamlined approach.

Once you get past all the "gotchas" in the necessary configs for using
VCB, it is really straight forward.  The NetWorker client config just
has "save_vcb.bat" in the backup command for the VCB proxy, and the
savesets list the VM guests to backup, i.e:

        VM:exchange.somewhere.com:*FULL*

What are the "gotchas" with VCB:

- you need a dedicated physical Windows host to be the backup "proxy"
- the VCB proxy must be SAN-attached to the same SAN as the ESX
  server(s) that it is backing up
- All ESX SAN LUNS must be presented to the VCB proxy (and windows
  must be configured to NOT auto-assign drive letters to the LUNS
- The VCB proxy must be presented the same hardware lun ids (HLU in
  EMC SAN speak) as they were presented to the ESX server(s) -- which
  also means that multiple ESX servers on the SAN being backed up by
  a single VCB proxy must all have unique HLU numbers.
- The VCB proxy requires significant available temp storage
  to copy the disk images to in preparation for going to tape
- The backup server and VCB proxy must resolve the same DNS info
  for the guests, and it must match the info the guest presents
  in Virtual Center
- Guest disk images spread across multiple LUNS cannot use the same
  filename on each lun, they must be unique
- You cannot backup raw luns
- Cannot backup VM's that are hosted on NFS or ISCSI
- Cannot restore directly into the virtual disk
- Error reporting for failed VCB backups is seriously lacking.  It
  regularly reports "Host is unreachable" errors, which can mean
  anything, which of course makes it a a pain to troubleshoot.

And the biggest hassle, is that if it gets any kind of an error,
it regularly leaves its snapshot behind.  Once it does that, it will
always fail subsequent backups due to the existing VCB snapshot.
To fix requires manually going into Virtual Center and removing the
VCB snapshot.

So what am I personally doing with our VMware/NetWorker environment:

I am currently running VCB full backups of each guest once per week,
with all my guests split up over 5 days.  These backups are for DR
purposes only.

That is currently working for about 80% of my guests (after migrating
to a new SAN and cleaning up LUN issues, i.e. fixing HLU numbers, no
shared LUNS between ESX clusters, getting rid of raw luns, etc).  I
still have a number of duplicate disk image names to clean up, plus at
least one known DNS issue (multiple interfaces on the guest, with the
guest reporting to VC as one, and DNS saying another).  The others I have
now clue about yet.

I am now also in the process of identifying critical windows hosts to install
NetWorker clients on to ensure I get good incremental data backed up to
tape, and I am using rsync scripts to stage my RHEL guests to disk for backup.
That way I can quickly restore incremental data, and I have the VCB backups
for DR purposes only.

What would be nice is if EMC would at least give us a break on NetWorker
client licensing for VMware Guests.

In the meantime, it looks like it might be worthwhile to take a look at
the new 3.x version of the vmbk.pl script in combination with savepnpc,
and/or rolling my own solution.

Rodney

David Mingia wrote:
We have the same dilemma...so, some post on this issue would be a good
thing.
I hear of some rumor that on VMWare v 2.X there were scripts floating
around to do it, but they don't work on 3.x

Right now we are also resolving the issue the way you are and installing a
client on each instance of virtual server.  There has got to be a better
cost effective way to do this.  (Are you listening Legato??)

David Mingia
Networks and Server Specialist
dmingia AT guilford DOT edu
Guilford College
5800 W. Friendly Ave.
Greensboro, NC  27410
336-316-2424


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