Compaq ProLiant 8500 ProLiant 8500 Server Technology - Page 17

TC000604TB TECHNOLOGY BRIEF (cont.) ... Hot-Plug Capability When a power supply is hot swapped, the microcontroller governs the power-up and power-down sequence, enables the health drivers to calculate redundancy "on the fly," and informs the health drivers of changes in load. Compaq hot-plug power supplies are readily identifiable by their portcolored bezel, as shown in Figure 11. Port-colored bezel Figure 11: Front view of hot-plug power supply with port-colored bezel. Hot-Plug Hard Disk Drives The ProLiant 8500 server supports four 1-inch, Wide Ultra-3 SCSI, internal hot-plug hard disk drives. The internal drives can be controlled by an Integrated Smart Array Controller (see "Storage Technologies") to optimize them for OS and boot support. When the server is configured for maximum capacity, it can support 73 GB of internal storage. Capacity will increase in the future as new drive technologies emerge. Auto Processor Bus Recovery Auto processor bus recovery is a feature of the ProLiant 8500 server that maintains server availability in the unlikely event that one of the cache accelerators fails. If a cache accelerator fails, the server will go through the Automatic Server Recovery (ASR) process and reboot. Typically, a failed cache accelerator would prevent the server from rebooting; however, auto processor bus recovery enables the server to recover and maintain availability of the processor bus with the good cache accelerator. With the server still available, the administrator can replace the failed accelerator at the most convenient time. STORAGE TECHNOLOGIES As corporations commit more critical information to computers, the requirements for more storage capacity and faster data movement are increasing at a startling rate. The Compaq ProLiant 8500 server includes new storage technologies that help meet these requirements. New hard drive technology and a specially designed integrated array controller allow the ProLiant 8500 server to deliver the highest levels of external storage capacity faster and with more reliability. Hard Drive Technology The Compaq ProLiant 8500 server uses low-voltage differential (LVD) Ultra-3 SCSI hard drives. Ultra-3 SCSI hard drives use a 16-bit bus and a double pumped 40-MHz clock rate to achieve maximum transfer rates of 160 MB/s. This bus speed provides the performance demanded by today's data-intensive applications and prevents system performance from becoming I/O limited as drive throughputs increase. 17