User manual

Setting up iXOS-JUKEMAN
iXOS-JUKEMAN 2.2 User Manual Pre.12/9748
3.4 Set up devices
Each device controlled by the server requires a description file that speci-
fies the device type, the SCSI address and properties of the drive, and the
SCSI address or RS232 address of the robot (changing mechanism). The
file also specifies which storage slots the server should use (default is all
slots) and an optional file that stores the contents of the slots. A device
can also be an ISO 9660 image on your hard disk, which is controlled the
same way as ordinary disks.
The following sections explains how to set up SCSI devices for iXOS-
JUKEMAN.
3.4.1 SCSI devices
This section summarizes the representation of SCSI devices by our ge-
neric SCSI driver.
Controllers, buses, IDs, and LUNs
A computer can use several SCSI controllers for multiple SCSI buses.
Each SCSI bus has 8 IDs, named 0-7. Normally, each device on a SCSI
bus requires a SCSI ID. Jukeboxes often need one ID per drive and one
for the robot.
Warning: When you connect devices to the bus, be sure the new devices
use IDs that are not being used by existing devices on the con-
troller. If you use an occupied ID, you can damage your hard-
ware.
Usually, the SCSI controller occupies ID 7, 0-6 are free for devices. SGI
computers occupy ID 0, which means you can connect devices using IDs
1-7.
Each SCSI ID can be split into 8 logical unit numbers (LUNs). The ad-
vantage of LUNs is that a jukebox only has to use one SCSI ID, so you
can attach more devices to a single bus.