ProLiant 8000

When your organization outgrows its server, you might need to make a choice: Implement a network of smaller servers or upgrade to a system that can handle your entire workload. An 8-way server might be able to handle your applications' crucial requirements, but when your chief financial officer (CFO) sees the price, you'll need to justify the expense. The Windows 2000 Magazine Lab tested Compaq's ProLiant 8000 to help you decide whether the system is worth the expense. The system lives up to its promises of improved power, memory, and storage, and I'll hate to send the server back.

Hardware Design Features
The basic ProLiant 8000 system has four processors, 2GB of Synchronous DRAM (SDRAM), a 4250ES RAID controller, and no OS. We tested a system that had eight 550MHz Pentium III Xeon processors with a 2MB Level 2 cache, 4GB of 100MHz SDRAM, twenty-one 9GB 10,000rpm-class disk drives, and a Compaq 4250ES RAID controller.

I remember the refrigerator-sized Pentium Pro processor-based 8-way servers, so I was pleasantly surprised to receive a system that is 24" x 17.5" x 24.5", rack mountable (14U form factor), and on casters. Three disk-storage bays are in the front of the cabinet. Each bay holds seven 1" hot-swappable disk drives. The combination CD-ROM and 3.5" drive is near the bottom of the system, so you can reach the drive when you mount the system at the top of a rack. The system includes two other front-accessible, half-height non-hot-swappable device bays. An LCD status panel—the Integrated Management Display—shows the system's power-on state and displays hardware alerts that the system firmware generates. The power status light is green when the system's power is on, and yellow when the power supplies are plugged in and the system detects a hardware fault. During our tests, the power status light turned yellow when a processor card wasn't properly inserted into its slot.

The system components you use most frequently are easy to access. Three lockable hinged doors in the top of the cabinet provide access to two hot-swappable cooling fans and the system's 11 PCI slots. Slot 1 is the only 32-bit PCI slot in the system; the other slots are 64-bit PCI slots. All the slots are 33MHz except slots 10 and 11, which are 66MHz slots. In addition, slots 10 and 11 have an extended SCSI connector to support Compaq's cableless RAID controller and SCSI connections. All PCI slots are hot-swappable and include individual power switches that let you turn off power to a slot when you insert or replace a card while the system is running. Windows NT 4.0 lets you replace a failed card, and Windows 2000 (Win2K) also supports new card insertion and autodetection during system operation.

The system includes three bridged PCI buses. PCI slots 1 through 4 are assigned to the primary bus, slots 5 through 9 are assigned to the secondary bus, and slots 10 and 11 are assigned to the tertiary bus. The slots are all tool-less. A cleverly designed plastic retainer clip rotates into place to secure a card. When necessary, you can use standard screws to secure a PCI card in place. You can see three system interlock LEDs through the open PCI slot covers. You use the LEDs and troubleshooting information from the Compaq ProLiant 8000 Setup and Installation Guide to diagnose power-related component and system-board interconnect cabling failures in the system.

Thumbscrews on the front of the system hold each of the side panels in place. The panel on the right side of the unit (viewed from the front) provides access to the CPU slots and the memory board. A plastic cover channels cooling airflow through the radiators affixed to each CPU. A separate airflow path cools each group of four processors, and a sealed liquid cooling system carries heat to 24 cooling fins on the end of each processor. The cooling system's design creates a longer, thinner CPU package than those which have the cooling fan mounted directly on the side of the processor. Two system cache accelerators (Intel calls them cache coherency filters) sit between two groups of four processors along with the Profusion chipset. More than one processor can have a copy of the same memory address in its Level 2 cache. The cache accelerators for each CPU bus retain a list of the memory addresses in each CPU's Level 2 cache and indicate whether several caches share the data and whether the data has been modified. Because of these lists, CPUs snoop the processor caches on the remote processor bus less frequently, reducing processor bus utilization and improving system performance.

The system memory board is located just below the CPUs. The board includes 16 DIMM sockets, paired to create eight banks. The board can support a maximum of 8GB of 100MHz SDRAM, and Compaq promises future support for 16GB. You can loosen a thumbscrew to easily remove the memory board's retaining bracket.

You access the two non-hot-swappable device bays through the right side panel. You use the preinstalled SCSI cable with a separate SCSI controller to support SCSI devices installed in the device bays. If you use one of the embedded SCSI channels for non-hot-swappable devices, you can't use the same SCSI channel for the corresponding hot-swappable storage bay. You don't need to remove the left side panel; it conceals only internal cables and power supply bays. The two side panels have identical diagrams detailing processor and memory slot usage.

The back of the server provides access to the three redundant power supply slots and a pair of redundant rear-mounted processor cooling fans. Connectors for the embedded VGA controller and the serial, printer, mouse, and keyboard ports are also on the rear. Cutouts for externally accessible SCSI connectors are located between PCI slots 4 and 5.

Several features support system availability. A new feature of the ProLiant 8000 is Auto-Processor Bus Recovery. The system's Profusion architecture places two sets of four processors on separate system buses. If one system bus fails, system operation can continue using only the remaining operational system bus processors. (For a brief description of Profusion architecture, see the sidebar "Profusion Raises SMP to New Levels." For a detailed description, see Tao Zhou, "Profusion Architecture," November 1999.) Redundant load-sharing power supplies, redundant hot-swappable fans, and hot-swappable disk drives have become standard features of high-end servers, and Compaq has added several other redundant components. CPU power supplies and remote-flashable system ROMs are standard. Also standard is a dual-port 100Mbps Ethernet NIC with support for failover redundancy, which is upgradeable to Gigabit Ethernet with a daughterboard. Even if the primary array controller fails, support for redundant array controllers lets you continue to access RAID-based data.

Every ProLiant 8000 includes the Compaq Smart Array controller model 4250ES. The ES in the model number indicates that the RAID controller has the Extended SCSI connector for cableless installation. The controller has no connectors that would let you use standard SCSI cables to attach disk drives. Three internal cables connect each of the three storage bays to the system I/O board instead of connecting directly to the RAID controller. The extended SCSI connectors in slots 10 and 11 carry the extra signals so you can install hard disks and RAID controllers without using any cables. A battery-backed 64MB cache is standard on the controller, and the battery and cache are on a daughterboard. You can move the daughterboard to a replacement Compaq 4250ES if the controller fails, and the system will complete write operations that were in process when the system failed.

Error-Correcting Code (ECC) cache protects your data from a complete memory-chip failure. The data format that the controller writes to disk drives is compatible with the previous- and next-generation Compaq array controllers and lets you upgrade the array controller without backing up and restoring data on the array. Two onboard processors enhance RAID performance. The array controller checks for data integrity on disk drives in the background and remaps bad sectors to enhance system availability. The controller supports RAID levels 0, 1, 4, 5 and 0+1 (mirrored stripe sets) and array capacity expansion during system operation. Three 80Mbps Ultra 2 SCSI channels support up to 240Mbps peak throughput.