Fans
In addition to the power supply fans, the system has an option board fan (see Figure 1-4, B) cabled to the I/O board (see Figure 1-6, K) and three CPU fans (see Figure 1-5, C, D and F) cabled to the CPU base board (see Figure 1-7, A, D, F and H). The three CPU fans (front and rear) are redundant in configuration. If one fan fails, its associated fan changes its rotating speed to high.
Peripheral Devices
The following paragraphs describe the Ultra2 wide SCSI-2 hard drive bays and 5 1/4-inch removable media drive bays.
Ultra2 Wide SCSI-2 Hard Drive Bays
The right side of the system contains up to three Ultra2 wide SCSI hard drive cages for 3 1/2-inch SCSI-2 hard drives (see Figure 1-9). Each hard drive cage has a hot-swap backplane that supports four drives. The backplanes require an 80-pin single connector attachment (SCA) connector on the drives you install.
A drive carrier is required as part of the hot swap implementation. A 3 1/2-inch peripheral between 1.0 and 1.6 inches high can be accommodated in each carrier. A drive is mounted in the carrier with four fasteners, and the carrier is retained in the chassis by a locking handle.
A fault light on the front panel board gives a general indication that there has been a fault on a hot-swap drive. Each drive has a set of three lights to indicate the fault or other status: power-on (green LED), activity (green LED), or fault (yellow LED).
Three hard drive cages
(EMI panel and exterior door shown open)
Figure 1-9. Ultra2 Wide SCSI-2 Hard Drive Bays
1-18 System Overview