Sun Microsystems Enterprise 250 Owner's Manual page 74

Configuration Rules
Disk drives must be Sun standard 3.5-inch wide UltraSCSI-compatible drives, either
1 inch or 1.6 inches high. UltraSCSI-compatible 1-inch and 1.6-inch high drives can
be mixed in the same system.
The SCSI IDs for the disks are hardwired on the disk backplanes. There is no need to
set any SCSI ID jumpers on the disk drives themselves. The SCSI target address
(SCSI ID) of each disk drive is determined by the slot location where the drive is
connected to its UltraSCSI backplane.
The disk drives share the internal SCSI bus with the SCSI removable media devices
in the removable media assembly (RMA). The removable media SCSI cable provides
the termination for the internal SCSI bus.
For information about implementing RAID configurations, see "About Disk Array
Configurations and Concepts" on page 189.
56 Sun Enterprise 250 Server Owner's Guide • June 1998