HPUX 10.20 and Ultrium 960's

[Lacrosse]

Does HPUX 10.20 support the Ultrium 960 tape drives

[Patrick Wallek · Accepted solution]

Even if it does work, I have to wonder if you will see any real benefit. If this is a SCSI attached drive, the fastest SCSI interface 10.20 supported, I believe, was FWD SCSI at 20 MB/sec.

I seriously doubt that this is a FWD drive. It is probably a drive that supports Ultra160 or Ultra320 connection. If so, you would have to plug it into a SE SCSI interface on the 10.20 box, which only ran at 10MB/sec (I think).

With that small of a pipe (either interface) I really doubt that you are going to be able to stream data to the drive fast enough to keep the tape moving. In all likelihood the the tape drive will write some data, stop, back up, wait for some more data, write that data, stop backup, wait for some data, etc........ (this is also known as shoe-shining). This severely impacts tape drive performance.

If you are hoping to speed up backups, I would be surprised if you saw any real benefit.

[Lacrosse]

These would be Ult960's drives in a MSL tape library so it would be fibre from the server to the library and I believe SCSI internal to the drive?

[Patrick Wallek]

Ahh...OK. With a fibre connection you might be able to stream data to the drive fast enough, but it will be dependent on where the data is coming from and the type of machine this is on.

I honestly don't know if it'll work or not. I would probably just attach it and run an ioscan and see what comes up.

[Bill Hassell]

The Ultrium 960 did not even exist when 10.20 went obsolete several years ago. That means no driver support nor application support (such as fbackup). While tar or cpio might work, the drive will experience severe wear because the computer can never keep up with the drive. These drives are extremely high-performance and need a more than 120Mb/sec to run at full speed with typical compression. This is far faster than disks used in 10.20 systems.

Now several of the Ultriums do have DRM (Data Rate Matching) and can slow the tape down to as little as 29 Mb/sec but even this speed will be very difficult to meet with simple tools like tar. The tape drive will have to pause, backup and restart when data starvation occurs, perhaps hundreds of times per tape. fbackup can start up to six parallel reader processes to keep the tape busy but I am fairly sure it will not work with Ultrium drives. The same will be true for Omniback (Data Protector does not exist for 10.20).

The last patch bundle (SUpport Plus) was Dec 2001 and 10.20 went completely unsupported (read: no new patches or enhancements) in 2003.