How can I change to a different SCSI controller?

If your new controller is directly supported in the OS and doesn't need a BTLD, skip the following paragraph.

Install BTLD if applicable.: Mount the btld floppy ( mount -r /dev/fd0 /mnt) and run btldinstall (btldinstall /mnt). That installs the driver, but hasn't told the system to USE that driver.

Identify the current disk driver by

[tt]grep Sdsk /etc/conf/cf.d/mscsi[/tt]

Your current driver will in column 2- examples "alad", "arad", "blad"

Identify what driver you need fby examining /etc/default/scsihas (if you used a btld, it's whatever you installed)

[tt]cd /etc/conf/sdevice.d[/tt]

Edit the current driver file and change the "Y"'s to "N" in the first column. For example, if your current driver is alad, you edit /etc/conf/sdevice.d/alad.

Edit the NEW driver file and change "N" to Y. Example, your new driver is "blad", you edit /etc/conf/sdevice.d/blad.

Next, cd /etc/conf/cf.d and edit mscsi. Change the driver column to match your NEW controller. For example, changing from alad to blad with vi:

[tt]:1,$s/alad/blad/
:wq[/tt]


Finally,

[tt]./link_unix[/tt]

Answer yes to boot by default and to rebuild kernel environment.

Shut system down and install new controller. If any problem, put back old controller and boot "unix.old" (just type [tt]unix.old[/tt] at the Boot: prompt)



.



cd /etc/conf/sdevice.d