Chapter
2
Operating the Enclosure
This chapter describes configuration rules for the enclosure, startup and shutdown
procedures, and fault detection. The Ultra SCSI configuration rules apply to the storage
device side of the enclosure, but do not apply to the host side of the array controller.
Other chapters in this guide contain detailed information about individual element
functions, operations, and error conditions.
Ultra SCSI Configuration Rules
Proper operation of the enclosure requires compliance with both the Ultra SCSI standard
and hardware configuration rules. In some instances, operating system-specific
configuration rules might also apply.
General
The following rules apply to the Ultra SCSI (FAST 20) bus for this enclosure:
■
Ultra SCSI redundant array of independent disks (RAID) subsystems transfer data at a
higher rate than FAST 10 subsystems (40 MB/s versus 20 MB/s).
■
Installing a FAST 10 storage device reduces the bus average transfer rate as follows:
❏
When the array controller communicates with the FAST 10 device, the
communication rate is FAST 10 (the maximum rate this device can handle).
❏
When the array controller communicates with a FAST 20 device, the
communication rate is FAST 20 (the maximum rate this device can handle).