dlt drives in K class servers

[Vito Sarducci]

I have a two Dlt7000's daisy chained in each of my K and N class servers. Is there a known issue regarding daisy chaining Dlt7000's and Dlt8000's on a single SCSI bus? some K classes are running 10.20 and 11.x. The server having problems is a 10.20 server.

I am experiencing intermittent backups that fail on the drives. One day its 1m, and on another day its 0m?

If there is anything document wise, can someone share this with me.

much appreciated,

Chris
chrisam@rocketmail.com

[Robert_Jewell]

One thing to note is that if they are running off of the HP-PB Fast-Wide SCSI board (28696A)is to check the firmware revision of the boards. Look at patch PF_ISFW3944 for more info if this is the case.

-Bob

[Michael Francisco]

I just looked this up for someone else... In the HP DLT Tape Library 15-Slot user guide, page 2-7 and 2-8 says "only DLT4000 drives are supported as daisy-chained".

Link to document --> http://www.hp.com/cposupport/manual_set/lpg28402.pdf

Hope this helps!
Michael

[paul courry]

The DLT7000's will run *just* well enough to drive you crazy. (Yes, this is a plagarization of another current thread)

DLT8000's must run on a HSC SCSI bus because it is the only bus with enough bandwidth to avoid saturation.

DLT7000's should have their own HPPB FW SCSI bus each because *two* will saturate the bus like you would not believe.

The penalty you pay for breaking these rules is squirlley problems like none you've ever seen with regard to the SCSI bus and the drives. You *will* have nightmares.

[Alexander M. Ermes]

Hi there.
HP_PB FWD SCSI for DLT 7000
HSC FWD SCSI for DLT 8000
Daisy chain : will flood your logs with SCSI bus errors.
If you want to run the DLT drives with full load and use the drives abilities on speed etc
the drive must go into streaming mode. That means, data msut be coming in in a steady flow.
The SCSI buses will be definetely overloaded with daisy chained drives. If it works by coincidence, the drives will not go into streaming mode, but windf the tape forth and back every time data come to it.
Hope, my two cents help.
Rgds
Alexander M. Ermes