homsy@icsi.berkeley.edu@ (George Homsy) (07/04/90)
I currently have a Sun 3/50, and a SCSI disk which I am trying to interface to it. The disk is a CDC 94211 (otherwise known as Imprimus or, more recently, Seagate). The problem is as follows: The first time a SCSI command 0 (a "Test Unit Ready" command, I believe) is sent to the disk, the busy light comes on on the disk and stays on, and the SCSI bus will no longer talk to the disk. I have had some success with the Sun standalone diagnostic program, by the following method: When diag says, "reset scsi bus...", I have to manually power cycle the drive. When the drive reinitializes, a command completion error is generated, and diag requests the sense. Following this, diag reissues the test unit ready command, and this time it succeeds! Following this, diag works beautifully: I can scan for defects, format the disk, partition it, label it, verify the label, perform seek, read, and write tests succesfully, etc... When I try and boot vmunix, when the si device driver is initializing, the busy light on the disk comes on and stays on, and the kernel goes happily on its way, not realizing there's a disk there. If I reinitialize the disk after booting (by power cycling the disk), and then try a dkinfo, the same behavior results: The busy light comes on and stays on, and dkinfo reports a command completion error, followed by a bunch of "no such device" and "no such disk" error messages. I get the impression there's a simple fix for all this, but I'm too inexperienced to know it yet... Suggestions, anyone? --George Homsy homsy@icsi.berkeley.edu (415) 642-4274 x 174 (w) (415) 641-7470 (h)