CompuServe Thread

#New HD: setting LUN #

8 messages in this thread
#185266From: Bob FingerFeb 12, 1995 10:49 AM
I have a friend who recently bought a Quantum Prodrive LTS 170 for his Amiga 2000 (w/ 68030 and 3.1 ROMS). He has been unable to get it to work. He was able to change the address via jumpers but cannot find any explanation on how to change the LUN (which, like the original drive is set to zero). The docs only say that the two drives must have different LUN's as well as different addresses, but do not say how to change the LUN. The drive does not show up as an icon in the Workbench window. Is it just the LUN setting or do we have to also do something else, like issue a mount command? Any help (and explanation of the difference between address and LUN), will be greatly appreciated. TIA, Bob. – Bob Finger, 70404,3110 @ 12-Feb-1995, 11:48:38 EST
#185291From: Keith MeyersFeb 12, 1995 2:41 PM
It doesn't sound like the LUN is giving you the problem. As long as the main addresses are different, the controller should find the drives. Although I've never seen one used, LUNs were created in order to attach another controller to the SCSI bus, and have that controller control up to another 7 devices, giving SCSI the ability to actually control up to 49 devices. (Seven main address controllers X Seven LUNS per controller = 49 devices.) Since you don't have a secondary controller but an actual hard drive, the LUN setting is usually ignored. What the problem sounds like is that the drive was not "preped" properly. In order for the drive to become recognized by AmigaDOS, it must be partitioned and have the "Rigid Disk Block" written to it. The software that came with the controller card does this, or the Amiga's own hard disk utilities can as long as it's told to look for the proper device setting (such as changing the Amiga's "scsi.device" to GVP's "gvpscsi.device"). Once this information is written to the drive and the system is rebooted, the hard drive will become recognizeable and formatable by AmigaDOS. Regards, Keith.
#185295From: Don Curtis/SYSOPFeb 12, 1995 2:59 PM
Keith, YOu're close. LUN's are so you can have multiple devices (not controllers) at each address. Since the host adapter (commonly called a controller) takes up 1 address, and can't have a LUN…you have the possibility of 8 devices at each of the 7 remaining addresses for a total of 56 possible devices on one SCSI bus. LUN's range from 0 to 7, just like SCSI id's range from 0 to 7, for a total of 8 LUNs per SCSI ID available. Don
#185401From: Bob FingerFeb 13, 1995 8:03 PM
Thanks for the reply. After I sent my message, I realized that my friend probably hadn't formatted the disk, and I completely spaced on the subject. Goes to show you what programming in Windoze will do to your brain. We'll give it another try this evening. Bob – Bob Finger, 70404,3110 @ 13-Feb-1995, 08:42:28 EST
#185294From: Don Curtis/SYSOPFeb 12, 1995 2:56 PM
Bob, Your friend apparently mis-read the docs, or the docs are confusing. Only SCSI devices with the same address need to have different LUN's, devices at different addresses don't need to have separate LUN's one from another. Your friend needs to prep the drive via HDToolBox before the Amiga will recognize it. (similar to FDISK in the MS-DOS world if you're familiar with that). Don
#185402From: Bob FingerFeb 13, 1995 8:03 PM
Thanks for your reply, Don. I totally "forgot" about formatting the drive. Duh. I think the docs, (as read to me over the phone), implied that the LUN _also_ had to be different, so that threw me for a while. Thanks again, Bob. – Bob Finger, 70404,3110 @ 13-Feb-1995, 08:45:31 EST
#185333From: Steve AhlstromFeb 13, 1995 12:29 AM
Leave the LUN alone. If your friend is using a modern SCSI host adapter just set the SCSI ID to a unique number then use HDToolBox to set it up. -sja
#185403From: Bob FingerFeb 13, 1995 8:03 PM
Thanks for your reply, Steve. Will give it a try later. Bob – Bob Finger, 70404,3110 @ 13-Feb-1995, 08:46:14 EST