On 10/13/97 17:02:01 you wrote:
+--- In our lifetime, "Gregory Gulik" greg@wwa.com wrote: | | | I heard once that the NetApps support DLT stackers (not | libraries) so you can automatically do multi-volume backups | without manual intervention.
Not sure which models are supported.
Anything that is simply a tape drive that runs in a "stacker" or "autoloader" mode (not a "smart" library mode) should work. I have had great success with Quantum's DLT-4700, and I believe (not positive) that for 7000-level backup, the Breece Hill Q.45 was currently the recommended choice. However, I don't see why something like the DLTStor from Quantum wouldn't work with a 7000 in it, or something like a DLT-7700, if they ever release such a product.
The problem with hanging a stacker off of the filer (or any machine for that matter) is that they have a strong tendency to hang. Thus you need to reboot the filer to clear the scsi fault. Not something I can do too frequently to my filer :)
Having done literally thousands of backups on Netapp equipment, I can honestly say that I've *never* had this problem. Tape drives may go bad, but I've never had it just "hang" due to a SCSI problem between it and the filer that requires a reboot.
Not sure if being able to send a scsi reset to the bus would clear the fault. Perhaps that would be an interesting feature request....
If the bus is truly "hung", any attempt to talk to the tape drive will hang, and the bus will automatically be reset after failed attempts to talk to the drive. So any old mt command should work.
If this is not happening for you, I suspect the problem isn't a SCSI bus "hang" per se, but is in fact something else. Certainly, power-cycling the tape drive should clear any problems; if you have to power-cycle the filer, I'm tempted more the believe that you had a "dump in progress" according to the filer's internal state (which is, IMHO, a problem, but a different one from what you mention). If it really is SCSI problems, I would encourage you (if you haven't already) to contact Netapp support... it could be something as simple as termination, or you might need a new cable or SCSI card. Finally, one could always suspect the DLT drive itself as having bad firmware or some other hardware problem... I can tell you that the DLT-4700 does work, so if you can get one to test, you might be able to use that the isolate where the problem is before fiddling with other components.
Perhaps I am taking your description of a bus hang too literally, and you actually are experiencing a different problem, but in that case I would need more detail to help.
Bruce