Compaq ProLiant 8000 Compaq ProLiant 8000 Server Technology - Page 18

TECHNOLOGY BRIEF (cont.) RAID - Redundant Array of Independent Disks ... Hot-Plug Hard Disk Drives The ProLiant 8000 supports up to three Wide Ultra-3 SCSI internal drive cages. Each ProLiant 8000 internal drive cage can support a maximum of seven 1-inch hot-plug drives (for a total of 21 drives with all three drive cages installed). When the server is configured for maximum capacity, it can support 382 GB of internal storage. Capacity will increase in the future as new drive technologies emerge. 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 8000 server includes new storage technologies that help meet these requirements. New hard drive technology and a specially designed array controller allow the ProLiant 8000 server to deliver the highest levels of internal storage capacity faster and with more reliability. Hard Drive Technology The Compaq ProLiant 8000 server uses low-voltage differential (LVD) Ultra-3 SCSI hard drives. These new one-inch drives allow the ProLiant 8000 server to support 21 total drives-three drive cages with seven hard drives each-for a maximum internal storage capacity of 382 GB of data. 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. Although the ProLiant 8000 server supports Wide Ultra-3 SCSI hard drives, the internal drive cages and the Wide Ultra-3 SCSI buses will run in Wide Ultra SCSI mode with the Smart Array 4250ES controller, which is a Wide Ultra SCSI device. Array Controller Technology The ProLiant 8000 server supports up to two Compaq Smart Array 4250ES controllers-providing high-performance and ease-of-use features. The Smart Array 4250ES controller offers three Wide Ultra SCSI channels, allowing a single controller to support all three internal hot-plug hard drive cages in the new ProLiant 8000 server. Since all three drive cages run off the same RAID engine, all 21 internal hot-plug hard drives can be configured as one massive 382-GB array or multiple smaller arrays. Additionally, the Smart Array 4250ES controller uses a 64-bit PCI Hot Plug extended SCSI connector and a cable-less design that is optimized for the ProLiant 8000 server. The extended SCSI connector gives customers the flexibility to accommodate both 64-bit and 32-bit technology. The cable-less design allows the hard drive cages to be directly connected to the I/O board itself, not the array controller. This means much easier PCI Hot Plug usage and the elimination of cumbersome loop-back cables. The Smart Array 4250ES controller supports RAID levels 0, 0+1, 1, 4, and 5. In addition, the controller uses a Compaq developed RAID 5 engine that optimizes RAID 5 performance. The controller also supports online spares, which improves overall system fault tolerance by automatically replacing a failed drive and quickly restoring the system to full RAID protection. The Smart Array 4250ES controller includes a robust 64 MB of battery-backed read/write cache. Rechargeable batteries are integrated into the cache, which is actually a removable card installed onto the Smart Array 4250ES controller base card. The removable DRAM and batteries keep posted-write data secure in the unlikely event that the base controller board should fail. If a system TC000603TB 18