Just for the record.  We have been doing lots of testing between the DTL4000
and DLT7000 to determine why the through put to the 7000 is not any better
than the 4000.  To date I have no explanation except that something in MPE
is creating an i/o bottleneck.

Our tests have proved that the 4000 and the 7000 are about the same speed on
an MPE system.  This performance problem was brought this to HP's attention
and I believe that HP is now working towards improving the performance of
Store.  Unfortunately, I do not have any details about how they will be
doing this or when the changes will be available.

I also tested several third party products and ran into the same issue.  The
only one that appeared to be able to drive a DLT7000 at capacity was Orbit
since it has the ability to have several processes writing to a single tape
drive.  This differs from Store or Road Runner which only have one process
per drive.

Here is an interesting test to prove to yourself that MPE cannot drive a
DLT7000/8000 at its rated speed of 10 MB/s with compression; do a store to
the device $NULL and then check the statistics at the end of the store.  It
will probably only give you around 5-6 MB/s through put.  The DLT7000/8000
to be fed ~10 MB/s to keep the device streaming.

Summary:  In my opinion, purchasing any backup device that can handle more
that 5 MB/s is a waste of money until HP can fix the performance of their
backup software.  Not that they offer any devices that fit this description
anymore.

I won't go into rant mode right now even though I really want to!

Carl McNamee
Systems Administrator
Billing Concepts

-----Original Message-----
From: Eben Yong [mailto:[log in to unmask]]
Sent: Monday, March 06, 2000 9:59 AM
To: [log in to unmask]
Subject: FW: DLTs 8000 Speed


DLTs 8000 SpeedGood questions...

1)  MPE 5.5p6.  DLT-8000s connected to our 996-300 as DEVs 51 and 52.
2)  STORE
@.PUB.SYS,@[log in to unmask]@[log in to unmask];;SHOW;DIRECTORY;PARTIALDB;ONLINE=START;PROGRESS;ST
ORESET=(*FULL1),(*FULL2);MAXTAPEBUF.  INTERleave is not being used... we
should try that.  Thanks.
3) HARDWARE COMPRESSION?  I am sure there is a "no duh" answer, and the
answer should be "YES", but I am not sure... how to tell?

-----Original Message-----
From: Coombs, Michael [mailto:[log in to unmask]]
Sent: Friday, March 03, 2000 4:24 PM
To: [log in to unmask]
Subject: DLTs 8000 Speed


Hello there,

Would be nice to know a couple of facts about your setup that could affect
the speed of your backup:

1) What version of MPE and size of machine are you using?

2) What parameters are you using on the STORE command?
(ie. Are you using the Interleave, Maxtapebuf and/or Compression options?)

3) Is Hardware compression enabled on the DLT's drives?

Just curious! :):):)

Michael L. Coombs
System Manager

Presbyterian Health Plan
2501 Buena Vista SE  Suite 300
Albuquerque,  NM  87106

Phone: 505-923-5435
FAX:    505-923-6121
Email:   [log in to unmask]