UFS filesystems on SCSI disks

[Keith Gabryelski]

mouse at thunder.mcrcim.mcgill.edu (der Mouse) writes:
> In article <1310 at creatures.cs.vt.edu>, alanlb at csgrad.cs.vt.edu writes:
> > I'm trying to create UFS file systems on a SCSI disk and have been
> > wondering what to specify for the number of tracks/cylinder.

I feel I should comment because this person is working with Amiga Unix
(his addressed tipped me off, but the real mark was the mention of
`rdb' the `rigid disk block' command for creating partitions under
Amiga Unix that are compatible with AmigaDOS.

Future inquires about Amiga Unix should be sent to comp.unix.amiga.
Follow ups to this article are sent to same.

> [... lots of text from `der Mouse' deleted, although it was useful in
>      a generic filsystem sense, it needn't be repeated ...]

Since, your message didn't claim you had actually gotten the
filesystem to work and it seemed to have some confusion about rdb
numbers in it I will include a complete description of how to add a
SCSI disk with a UFS partition to your Amiga Unix machine.

To setup a UFS filesystem under Amiga Unix you need to create a
partition table.  Do this with the rdb command:

Find the SCSI ID of the disk.  Do this by looking in the drive manual
and setting the appropriate jumpers on the drive.  Make sure this
number does not interfere with other SCSI devices connected to the
system (Your root disk is probably `6'--maybe `0', Tape drives are
usually `4', and the controller itself is `7'.

Connect the drive to your machine.  Turn your machine on, if it
doesn't boot you've probably done something wrong.  Most likely the
drive ID for the extra drive matches the root drive.  Try again.

login as root.

type the command:

	ddsize /dev/dsk/cXd0s0

(where `X' is the SCSI ID.  The output of this xommand is the size of
the disk in blocks.)


Now, make a partition using rdb:

	rdb -c /dev/dsk/cXd0s0 NAME 128 SIZE

(where `X' is the SCSI ID, NAME is some string, and SIZE is the number
returned from ddsize minus 128 (which is the start block of this
partition)).  To create two partitions, you would do:

	rdb -c /dev/dsk/cXd0s0 NAME1 128 SIZE1 NAME2 START2 SIZE2

NAME1 & NAME2:	are strings used to indentify the partition.
SIZE1:		size of the first partition
START2:		SIZE1 + 128 (start block of second partition)
SIZE2:		size of second parittion (the output of ddsize - 128 - SIZE1)

Now, make a ufs filesystem on the first partition:

	mkfs -F ufs /dev/dsk/cXd0s1 SIZE

(where SIZE is the size of the partition [SIZE in the first example, SIZE1
in the second])

To make a ufs filesystem on the second partition, do:

	mkfs -F ufs /dev/dsk/cXd0s2 SIZE2

You can now mount the partition:

	mount -F ufs /dev/dsk/cXd0s1 /mnt

or place a well-formed entry in /etc/vfstab:

/dev/dsk/cXd0s1 /dev/rdsk/cXd0s1 /mnt	ufs	1	yes	-

Pax, Keith
-- 
Keith Gabryelski                                 Advanced Products Group
ag at amix.commodore.com                                 ...!cbmvax!amix!ag