D8602A and LP8000 Co-Existence

[Andy Bloor]

I have a backup SAN with multiple NT4 SP6a servers attached via D8602A / Brocade Silkworm 2800 to a SureStore 4/40 library. Veritas Backup Exec is in use and all was well for 5 months.

An additional server was added, which had 2 x LP8000-EMC cards installed directly attached to EMC Clariion disk. I added a D8602A and attempted to install the HHBA5100.SYS driver for the card, and the server hung. This was re-tried with the same results. After a reboot I noticed the card was working, and could see the tape drives and library, using the already installed LP8000 drivers !! After much testing all appeared OK and the solution was left operating.

In hind-sight, there have been many intermittent problems since this server was added, including drives going offline, poor performance of backups etc.

I have the latest drivers for the D8602A and wonder if these will now install alongside the LP8000 drivers ? I haven't tried yet. The driver I tried previously was shipped with the HBA's around December 2000.

I believe if I could get the correct driver for the D8602A installed my problems would dissappear....

Any help appreciated.

[Steve Bonds]

I've had nothing but problems mixing tapes and disks on the same SAN. In fact, I've had nothing but problems with tapes on SANs in general.

The problem is that any time a SCSI inquiry goes out on the SAN many (most) tape drives will stop what they are doing to respond to it. This generally interrupts your backups and often causes the drives to stop responding altogether.

SCSI inquiries are common when systems reboot or probe the IO bus (i.e. HP-UX "ioscan", starting up NT's Disk Administrator, etc.)

I recommend either aggressive SAN zoning or moving the tape drives off the SAN and using LAN-based backups to a single server (or failover set) where the drives would only be accessible to one system at a time.

[Andy Bloor]

I have only the tapes on this SAN, as the EMC disk is currently direct attach to the LP8000 HBA's.

Backing up through a single backup server is not feasible as I am currently acheiving around 35GB/Hr from each server to a single tape drive. I have two drives therefore 70GB/Hr throughput. I cannot get this type of throughput accross a LAN, through a single server.

After speaking to HP / Microsoft / EMC the next action is to de-install all HBA's and remove their associated drivers, install the D8602A and its driver first, then install the LP8000's and their drivers. HP say that the driver for the D8602A 'should not' pick up the LP8000 cards..... We will see. If this is successfull I believe it will resolve the issues, as prior o the introduction of this server I had no issues.