SUMMARY: Backup Hardware

From: Sizemore, Joanna <>
Date: Wed May 15 2002 - 11:19:30 EDT
Thank to all for the advice and recommendations.  Especially:  Jim Southerd,
Jeff Kennedy, Moti, Jed Dobson, Marcelino Mata, Penney Jaye Deeney,
Christophe Dupre, Andrew Stueve,  David Foster (who included a very
informative white paper that I will share if anyone wants a copy), Vincent
McIntyre, Raghu, Stuart Whitby.  I have a lot of information to digest but
thought I would go ahead and post a summary.  No clear cut answers, but good
information none the less so I have opted to post the responses instead of
trying to summarize.

Not familiar with various media, but one thing I know is that Veritas has
agent for Solaris as well.

So you can run the Veritas backup on an NT and it will back up all your
Microsoft and Unix flavor files.
The Unix agent actually allows you to specify which partitions and
directories on the Unix box you want backed up.
I am using two qualstar libraries
one with 100 tape slots and 6 ait2 tapes and one with 12 slots and two ait2
tapes .
I like both the performance and ( so far 2+ yrs ) 0 maintenance .
I would go with ait as it has proven to be fast and reliable.
as for the old dlt's just keep a system on the side for restores ....
just my 0.2 cents
How many servers, how much storage? I would go for a mixed-media library
and use DLT & a new technology. AIT and LTO are the big ones. I personally
like LTO. There are several manafacturers of these now incld. IBM &

For software Veritas NetBackup wins hands down. Legato is clumsy compared
to NetBackup. I like the GUIs much better for NetBackup it is more
complex however.
It all depends on amount of data, backup windows and cost you want to spend
on media, drives and libraries.

We use Veritas Netbackup on NT to backup Solaris, AIX and Tru64 and Windows
server.  We use a 15 slot AIT-1 library but we are moving to AIT-3 15 or 30
slot library.  

This solution will be fine as long as we do not backup more than 250Gb in
one night.  That is the most we can backup over 100Mb/s network.

We find that AIT drives are more cost effective than other solutions we have
looked at.  Then again, I have not looked at SDLT or LTO lately.  The
library is the Spectra 2000 made by spectralogic.  It costs around $11,000
There have been several discussions about ait vs dlt tapes on the
Legato NSR (Networker Save and Restore) list.  Networker is software that
manages backups, a la Veritas.

This is not a Networker or Veritas endorsement, but you can check out the
information on ait and dlt tapes/drives at:

I think you need to subscribe to the list, but you can do that online and
unsubscribe when you're done.

Manufacturer really depends. Many are really good - but it's probably
best, from a support point of view, to stick to your backup server
manufacturer. Here we have a Sun server doing backups, so we bought a Sun
tape library (which Sun OEM from StorageTek). So we get good StorageTek
hardware, but a single source of tech support, which is really convenient.

For the technology, SDLT and LTO seem to be the way of the future. SDLT is
Quantum's technology while LTO is backed by several manufacturers (IBM and
Seagate, among others). I would tend to go the multi-manufacturers way
myself. For your several years worth of DLT, you should keep your current
drive as neither is compatible anyway.

I'm assuming an 8 hour backup window.  Technically 1 SDLT drive would
accomplish this right now.  I have a single SDLT drive and it streams
regularly at 25mb/sec (assuming your clients can keep it going); but
let's pad that a bit.  20mb/sec = 1200mb/min = 72gb/hour = 576gb/8hrs.

However, you may not have enough resource or horsepower to drive the
tape at that speed, so if you pad it with another drive you should be

As to libraries; I have an ATL P6000, which is probably overkill in your
case but maybe not, depends on growth potential.  ATL makes an M1500
that has 2 SDLT drives and holds 21 tapes.  This is enough capacity for
your needs but may require you changing tapes more often than you would
like.  I would personally look for a library that kept me from changing
tapes at all, only eject/inject for offsite.  The P1000 may do it for

Of course there are other library makers....but I woudl look for
something that could hold at least 4 SDLT drives (or some other uber
drive of your choice) and 400 slots.  If you plan to expand fast I would
say 8 drives and 600 slots.
Just a quick thought, while you are going to get a bunch of replies 
concerning hardware, how many tapes, etc., something else to consider is 
the backup window that you have.  How long is your system going to take 
to backup that data?  Depending on your window, that could impact how 
many drives backing up concurrently, and how fast the drives are (DLT 
slow, but high capacity - AIT drives fast, but expensive and lower 
We use AIT tapes, not at AIT-3 (100GB/tape, 36MB/s). The drives
are expensive, but the capacity and speed make up for that, as
does the reliability of the drives. We haven't had a single failure
in over 4 years of use of 4 drives (started with AIT-1).

I've attached a document comparing tape technologies, it's from Take it with a grain of salt, it comes from
a company which makes libraries using AIT, but it's conclusions
agree with everything I've heard in surveys, articles and from
talking with vendors.

We use a Qualstar tape library, the price is very good and they
are known to be very reliable. We haven't had any problems with
we use a tape silo + robot sourced from StorageTek (9710 library, with
500 tape slots). the tapes are DLT700. Monthly full b/u 1.3Tb spread
over 3 sites. Not clear what we would do if we started over from scratch,
AIT looks attractive but we have yet to hear of someone using it in

One word answer sun L180 with veritas netbackup.

If you've already "standardised" on DLT, go for SDLT in 
a smallish jukebox like a STK 9730 if you're looking to 
"improve" on what you've got.  Alternatively, stick with
straight DLT and get extra drives.  However, take into 
account how you will manage the jukebox.  If you're 
looking to use one jukebox with NT backup and Solaris 
backup, you're going to need something to manage which 
software is allowed to use which tapes in which drives.
If you're running NetWorker (since I know it well), you
can set up your jukebox to give all of your bigger 
servers local drives to back up to, and let it manage 
all your backups.

Just got to your second post, since my VPN was down when
I tried to send this one.  I'd guess something like the
9730 would be fine for you:
Alternatively, something from ATL is always a good choice,
and they seem to have more parts on hand when you've got a

Given your storage needs, I'd recommend one piece of 
network backup software which will handle all of your 
backup requirements.  Legato NetWorker (Solstice Backup) 
and Veritas NetBackup are the two main options in this 

Joanna Sizemore
Data Integration Manager
Grote Industries, LLC
v (812) 265-8857
sunmanagers mailing list
Received on Wed May 15 11:36:37 2002

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