cannot see DLT7000 tape device after power down/up

[Michael Campbell]

We did a power down over the weekend and on coming back up the server is not seeing our external DLT7000 drive. There's power going to the device and it seems to operate ok (accepts tapes etc.) but ioscan is not picking it up.
The server is running HP-UX 11.0.

Any ideas ?

[melvyn burnard]

ioscan -f?
are the cables and terminators ok?

[Paul R. Dittrich]

I would try "insf" and make sure the DLT was powered up BEFORE the boot process.

HTH,
Paul

[Michael Campbell]

We are 90% sure that the DLT was powered on before the server. The tape drive is on it's own SCSI bus, should we be able to reboot the drive without rebooting the server?

Thanks for your help with this.

MC

[melvyn burnard]

Yes, you could do htat , but again you need to run ioscan -f to force the system to go look at theio and "see" the drive
You could also try
ioscan -H (device hw path)

[Pete Randall]

Michael,

I had an issue a couple years ago where the DLT's would just vanish. I had a C.E. on site several times replacing cables, replacing SCSI cards, trying various sequences of power up/down. We never did come up with a definitive answer. They started working and have ever since but I'm scared to death to do anything to them.

Make sure your cables and terminators are properly seated - disconnect them and reconnect them at both ends, then try the ioscan -f and see if they show up. You might also want to reboot the server when possible.

Pete

[Eugeny Brychkov · Accepted solution]

To (re)discover devicees you should use 'ioscan -f', as many responces state, because it will go into process of pollin each path scanning for new devices. If, after issuing 'ioscan -f', you will not see device in the list, it means that device is not found by system, and you have connectivity problem (at least). You have to check whole bus - SCSI cables, terminators, and other devices attached if they can influence bus operation. Standard troubleshooting methods are:
- move this device to well known good configuration, and see if it will be identified. If not, then problem is with device;
- move another well known device into this bus. If device will not be identified then problem is with the bus;
- replace all components on the bus (cables, terminators), disconnect all other devices, leaving only desired device on the bus
Eugeny