SLR 5 Tape drive vs DAT

[Bill Vermillion]

On Wed, Feb 02 09:08 , Men gasped, women fainted, and small children 
were reduced to tears as Lerebours, Jose confessed to all:" 

> Scott posted:

> > One of my customers has an old QIC tape drive that has
> > finally died.

> > I told him to get a quote on a DAT drive to replace it.

> > The hardware guy quoted him a Tandberg SLR 5 Tape Drive for $610.

> > How does this compaire to a DAT drive.  This customer only 
> > has about 2gb
> > that needs to be backed up.

> > What really got my curiosity up is the fact that they quoted
> > hime $50 each for the SLR 5 Data Cartridges. What makes them
> > so expensive?

> DLT tapes can cost $50 and over in a heart beat. The greater
> their capacity, the more they cost. I guess this applies to SLR
> media.

> For 2GB, it is overkill to go that route. Buy a DDS4 tape drive
> and buy the media for about $8.00 each. The tape drive should
> cost $200 to $350 (Check http://www.pricewatch.com). Heck, if
> you go DDS2 or DDS3 you can still get the job done and have it
> installed for under $300 with 7 cartridges.

You really don't want to go with DDS2 if possible.  The DDS3
gets more data on the tape and therefore tape backups will
be faster.

Now if you argue that 'these are done overnight so it won't make
any difference' look at it this way.

I had a client with and original system when they had not a lot of
data - and it would take about 4 hours to backup and 4 hours to
verfiy.  That's 40 hours/week of drive wear.

When they went to DDS2 is got better.

But when they went to DDS3 the speed increased dramatically as the
designs of the DDS3 was fundamentally better.

Data going to a DDS3 was written typically twice as fast as
that on a DDS2.   As things got bigger they had to migrate to a
DDS4 to get everything backed up.

But if you have a DDS2 with a 2 hour backup and 2 hour verify and
compare that to a DD3 at 1 hour back and 1 hour verify,
you go from 4 hours a night to 2 hours night.

That means that a DDS3 will probably last you as long as the
computer it's on and may be able to be migrated to a new machine,
while the DDS2 may not last as long as the computer is in
operation.

I had one client who went through three DDS2 devices in the
lifetime of their server, while those with the DDS3 never had
problems.  All were on the Sony devices as even in the same type -
eg DDS3 - the Sony's were faster at backup/restore as they
had a slight difference in design.

Don't base your decisions on first time cost.  You need to analyze
the amount of data being stored and verified, and the do a bit of
math.

OTOH I had a client with a DDS2 and his nightly backups were always
under 20 minutes.  That lasted as long as his server did.

Bill


-- 
Bill Vermillion - bv @ wjv . com