Is is possable to share a DLT drive between 2 servers?

[Alan Casey]

We have and A-Class and N-Class (rp7400)
And would like to share a DLT drive (C6379A) between them, all VHD SCSI.

Is this possable? If so has anyone achieved this?

[Jan Klier · Accepted solution]

Technically you can connect the drive to more than one system. However, you need through discipline or process guarantee that only one host access the drive at any given time. Accessing the drive from multiple hosts simultaneously will generate unpredictable and nasty results.

To accomplish this, you must connect the HBA on one system to the drive, then from there to the HBA on the other system. One of the HBAs must be re-configured to use a Target ID different from 7 (the default for HBAs). And you should not have any terminator on the device, but insure that the HBAs are properly terminated or have auto-termination.

Can be done, but is tricky.

[Michael Tully]

Hi,

Yes it can be done, but beware of
the consequences if something does
go wrong. You would be better served
by having it local to one server and
using it to backup the other remotely.

-Michael

[Angus Crome]

There is another option, although most won't agree with it. There are a few companies that sell SCSI switches for sharing scsi devices (yes, it does work for tape drives). There are caveats though, the devices are almost as expensive as another tape drive, so you would want to share between more than just two servers, and you generally have to dedicate a SCSI channel on each server to it. The reason for this is that they generally cause many bus resets while switching/locking to an individual server. I would not recommend it, but it is still an option. I think black box sells one, as well as some of their competitors.

Finally, HP will definitely not support it. You would have to disconnect and test before they would be inclined to help with any tape issues.

It might have consequence with doing ignite recoveries as well.