The slot load Xserve computer has four internal bays for hard disk drives and the cluster node Xserve computer has one internal bay. Depending on the configuration purchased, some bays may be empty. The slot load Xserve also contains a single CD-ROM drive or a build-to-order Combo drive.
CD-ROM Drive
Combo (DVD-ROM/CD-RW) Drive (Optional)
Hard Disk Drive Bays
The slot load Xserve computer has a slot-loading 24x-speed CD-ROM drive on the front of the enclosure.
The CD-ROM drive is connected by way of an Ultra DMA/66-capable interface on the KeyLargo IC. The interface supports DMA Mode 2 data transfers to and from the CD-ROM drive. The CD-ROM drive is an ATA-33 device and is Device 0 (master).
The Xserve slot load computer can have an optional, slot-loading, build-to-order combination DVD-ROM and CD-RW drive.
The Combo drive can read DVD media and read and write CD media, as shown in Table 3-7. The DVD-ROM/CD-RW drive also provides DVD-Video playback. (The G4 microprocessor provides the MPEG 2 decoding.)
Table 3-7 Media read and written by the Combo drive
| Media type | Reading speed | Writing speed |
|---|---|---|
| DVD-R | 8x (CAV max) | – |
| DVD-ROM | 8x (CAV max) | – |
| CD-R | 24x (CAV max) | 24x (ZCLV) |
| CD-RW | 24x (ZCAV max) | 10x (ZCLV, for high speed media) |
| CD or CD-ROM | 24x (CAV max) | – |
Digital audio signals from the Combo drive can be played through the sound outputs under the control of the Sound Manager.
The slot load Xserve enclosure has four drive bays for fixed-media mass storage devices. For software applications, the bays are numbered one to four from left to right. In Open Firmware, the bays are numbered ultra0 to ultra3 from left to right. The cluster node Xserve enclosure has a single drive bay on the left, which is numbered as 1.
Each drive bay supports a hot-pluggable ATA/133 disk drive using an Apple Drive Module (ADM): a single unit that combines an ATA/133 hard drive mechanism, a translation board to support hot-plugability, and a drive carrier. A problematic drive can easily be removed and replaced with a new ADM while the system is running.
Figure 1-1 shows a drive carrier with its two LEDs. The top one is a multicolor LED indicating drive state as follows:
The bottom (blue) LED indicates the individual drive’s disk activity.
The monitoring software supports only drive modules manufactured by Apple.
The Xserve computer has four ATA/133 (ATA-6) buses, which also support ATA/100. Each bus is connected to a single ADM, which is permanently configured as a master. No jumpers are used and no drive configuration is needed.