DAT40x6e - Hard drive goes missing

[Julian Griffiths]

Hi,

I connected a DAT40x6e to the external SCSI connector of a server and started the computer. After post I got a message about no boot device.

A closer check showed that the internal SCSI hard drive was not showing up in the list of SCSI devices, only the DAT drive. The SCSI card is an Adaptec 2940U2W and the hard drive is a Fujitsu MAB3091SP.

Disconnecting the tape drive and rebooting immediately restored the hard drive.

I checked the settings of the scsi card, hard drive and DATt device and they were OK. The hard disk is connected to the internal 68 pin ultra-wide connector and the tape to the external U2 connector. So they are on different SCSI buses. Tried again - same problem!

The DAT drive, SCSI card and hard drive are all known to work, but not together.

What's going on and how do I resolve this??

David

[Stuart Whitby]

Are you sure these are different buses? Internal ribbon cables and external connectors are different, but serve the same purpose. The external connectors are (theoretically) more robust though.

First thing to check is the SCSI ID of your DAT drive. My guess is it's conflicting with the hard drive.

I also wouldn't recommend installing these on the same bus - they use completely different blocksizes and performance will suffer with both in use.

[Julian Griffiths]

The card has two internal connectors and one external. The external and one internal are Ultra 2 LVD and the other is Ultra Wide. According to the Adaptec literature they are separate buses.

The hard disk is ID 0 and the DAT drive is 5.

[Julian Griffiths]

It turned out to be a faulty SCSI cable to the DAT drive!

[Julian Griffiths]

See previous entry.