Path: utzoo!utgpu!cunews!bnrgate!brtph3!brchh104!brchs1!bnr.ca!rice.edu!sun-spots-request
From: sun!synergy!kevin@corp.sun.com
Newsgroups: comp.sys.sun
Subject: Re: HP SCSI 2 drive booting problems (now SCSI ID mapping)
Keywords: Formats
Message-ID: <1606@brchh104.bnr.ca>
Date: 13 Feb 91 22:03:00 GMT
Sender: news@brchh104.bnr.ca
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Original-Date: 8 Feb 91 03:28:28 GMT
X-Refs:  Original: v10n25
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In article <1361@brchh104.bnr.ca> faatcrl!jimb@gvlv2.gvl.unisys.com (Jim Burwell) writes:

>Also, does anyone know how Sun binds SCSI IDs to device names ?  ID 0 maps
>to sd0, ID 1 maps to SD2.  What ID does sd1 map to ?

On the older machines, it is a config line like this:

disk            sd0 at si0 drive 0 flags 0

where the drive number is target*8 + lun (logical unit number).  We
ususally set up the config file so that 0 and 1 were the disks on the
first controller, and 2 & 3 the logical units on the second controller.

disk		sd2 at si0 drive 8 flags 0	# target 1, lun 0
disk		sd3 at si0 drive 9 flags 0	# target 1, lun 1

A little known fact is that you can enter the numbers in octal as well as
decimal, which makes things easier for SCSI devices.  The above lines
would then read:

disk		sd2 at si0 drive 010 flags 0	# target 1, lun 0
disk		sd3 at si0 drive 011 flags 0	# target 1, lun 1

The unit number (as in sd#) is mostly arbitrary - what comes in the drive
field is what counts for SCSI addressing.

For the newer (open prom) systems, the addressing is explicit, and the
drive number is again arbitrary.  It is a good idea to keep them
sequential and monotonically ascending.

disk sd0 at scsibus0 target 3 lun 0     # first hard SCSI disk

	l & h,
	kev