Hello all,

Just thought I'd share a solution that we placed in production to get
around a major problem with netbackup that we've been faced with over the
years..

the problem being with the fact that we keep buying faster and faster tape
technologies that are, in some cases, grossly outperforming the speeds of
the incoming backups..

We generally have two types of data that we backup:

1) large production data:  15-20TB of fast RAID disk
2) slow single unix system disks, Macs, NT boxes, etc:  1-2 TB

the new ultra-fast tape drives work just perfect when backing up the 20TB
of fast RAID disk..  

BUT, what we then run into is the fact that we still need to backup 1-2TB
of relatively SLOW disks..  especially an array of Mac boxes that like to
backup at around 500k/sec..  

what we run into at this point is these types of backups killing our
overall performance and sucking up major tape resources (backing up a 50GB
disk writing at 500k/sec to a 25MB/sec tape drive really sucks)

we've tried multiplexing things to death but there are multiple problems
with that setup..  it helps but certainly does not solve this problem
which is just getting worse with time.  

SO, we decided to write some scripts and do some "disk staging."

IE, we now write all of our slow backups directly to a local disk on the
media server.  once the backup is done it will kick off a duplication of
that image to tape, checks to make sure that worked correctly, changes the
primary copy to the tape version and then deletes the disk copy.

Viola, problem solved.  we have some scripts to automate adding/removing
classes from using the disk staging to make this easier to manage.

we've been running this for about 6 months now and it's pretty darn solid.
the scripts took about 2 days to write and we now backup all of our data
in a much smaller period of time.  our overall tape throughput went from
about 5MB/sec to about 22MB/sec..  I like those kind of results from my
perl scripts!

Jon

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Walt Disney Feature Animation      The Secret Lab
Senior Systems Engineer              818.553.6329
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