|
Re: [Networker] Backingup wondows Profiles with LTO 4
2009-06-09 16:17:48
Hi Frank,
On 10/06/2009, at 05:38 , Terveen, Frank wrote:
We are running a Windows only
Networker 744 network with a clustered file server
Using a Quantum lto 4 robot we are trying to get a decent throughput
for the backup
All servers perform rather well
Except the file server
we got support saying this is because of the amount of small files
Any reference would be nice on backing up profiles on windows
I canlt believe this drops down performance to less than 10 mb per sec
It's very difficult to keep data streaming directly to LTO-4 drives,
and one of the areas (past regular hardware bottlenecks) that will
cause problems is any issue surrounding dense filesystems. A dense
filesystem is one where the number of files on the overall filesystem
are sufficiently high that the time taken to walk the filesystem
starts playing a factor in the time taken to backup. (Therefore you
don't have to have a "big" filesystem to require a "dense" filesystem,
and typically the more the number of smaller files, the greater the
chance.)
There's a few options - using the SnapImage module will let you do
block level backup with file level recovery, BUT it comes at a cost
that the performance of file level recovery of files and directories
that were heavily fragmented will (let's not mince words here) suck.
As has been discussed a few times on this list, it's very difficult
and problematic driving higher speed tape drives at full speed with
direct-to-tape backup scenarios, and perhaps the most common/preferred
solution is to actually put some layer of disk in the backup solution
- e.g., backup to ADV_FILE devices, then stream large individual-file
savesets directly to tape from the ADV_FILE devices via cloning and
staging.
I've got an article on this at my blog that expands somewhat on the
above: http://nsrd.wordpress.com/2009/05/25/impact-of-high-speed-tape-on-backup
Cheers,
Preston.
--
Preston de Guise
"Enterprise Systems Backup and Recovery: A Corporate Insurance Policy":
http://www.amazon.com/Enterprise-Systems-Backup-Recovery-Corporate/dp/1420076396
http://www.enterprisesystemsbackup.com
NetWorker blog: http://nsrd.wordpress.com
To sign off this list, send email to listserv AT listserv.temple DOT edu and type
"signoff networker" in the body of the email. Please write to networker-request
AT listserv.temple DOT edu if you have any problems with this list. You can access the
archives at http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER
|
|
|
