Contributed by David O'Brien
<obrien@FreeBSD.ORG>
26 April 1998
Lets say we want to add a new SCSI disk to a machine that currently only has a single drive. First turn off the computer and install the drive in the computer following the instructions of the computer, controller, and drive manufacturer. Due the wide variations of procedures to do this, the details are beyond the scope of this document.
Login as user root. After you've installed the drive,
inspect /var/run/dmesg.boot to ensure the new disk was found.
Continuing with our example, the newly added drive will be sd1
and we want to mount it on /1.
(if you are adding an IDE drive substitute wd for sd)
Because FreeBSD runs on IBM-PC compatible computers, it must take into
account the PC BIOS partitions. These are different from the traditional
BSD partitions. A PC disk has up to four BIOS partition entries. If the
disk is going to be truly dedicated to FreeBSD, you can use the
dedicated mode. Otherwise, FreeBSD will have to live with in
one of the PC BIOS partitions. FreeBSD calls the PC BIOS partitions,
slices so as not to confuse them with traditional BSD
partitions. You may also use slices on a disk that is dedicated to
FreeBSD, but used in a computer that also has another operating system
installed. This is to not confuse the fdisk utility of the other
operating system.
In the slice case the drive will be added as /dev/sd1s1e.
This is read as: SCSI disk, unit number 1 (second SCSI disk), slice 1
(PC BIOS partition 1), and e BSD partition.
In the dedicated case, the drive will be added simply as /dev/sd1e.