IBMs Unix Server Is Scalable, Fast

IBM's latest midrange enterprise Unix server, the pSeries 660 Model 6H1, offers plenty of processing power and high availability features.

IBMs latest midrange enterprise Unix server, the pSeries 660 Model 6H1, offers plenty of processing power and high availability features to tackle e-business applications in todays Web hosting, ERP and CRM environments.

As a member of IBMs extensive lineup of Unix eServers, the p660 provides an upgrade path from the companys older RS/6000 Unix servers. The RS/6000 server line was rebranded late last year under the pSeries name.

The p660 provides 64-bit SMP (symmetric multiprocessing) with as many as six 668MHz RS64 IV microprocessors and 32GB of memory, making it highly scalable. The p660 can also be configured with one, two or four 600MHz RS64 IV or 450MHz RS64 III processors.

Latest AIX now available

The p660 started shipping early last month with Version 4.3.3 of IBMs AIX operating system, which can handle the concurrent operations of 32- and 64-bit applications. As of the end of last month, the p660 was also available with the new version of AIX, 5.1, which includes enhancements such as Linux API support for compiling Linux applications to run on AIX and 32-way SMP support.

IBM prices the entry-level system at $20,995, which makes it competitive with other midrange Unix servers such as Sun Microsystems Inc.s Enterprise 3500 and Hewlett-Packard Co.s HP9000 K class.

But the IBM system can quickly become quite expensive. For instance, the fully loaded rack-mounted configuration that eWeek Labs tested sells for $344,811. It includes six 64-bit RS64 IV 668MHz processors with 8MB of Layer 2 cache, 24GB ECC (error- correcting code) synchronous dynamic RAM with a Chipkill memory feature, two internal hard drives, two PCI Gigabit adapters, a PCI RAID controller and a disk enclosure with 14 Ultra 160 18GB hot-swappable hard drives.

The p660 package includes a Central Electronics Complex unit that holds the processors, system boards, memory and internal hard drives; and a separate I/O drawer that holds the 14 hot-pluggable PCI slots (10 64-bit and four 32-bit). The entire system takes up 10U (17.5 inches) of rack space.

The RS64 IV microprocessors use IBMs copper and SOI (silicon-on-insulator) chip manufacturing technologies. The copper circuitry provides better conductivity than aluminum in a smaller footprint that accommodates more performance-enhancing features. The SOI process increases processor efficiency and reliability by allowing the processor to run with less power.

In tests, we configured the p660 to provide file-sharing services to 60 Windows NT clients using Samba 2.0 for AIX. We used AIXs Journal File System mounted on the disk array with a RAID 5 configuration.

To implement the system, IT staff must have some familiarity with AIX, although people who know Linux or Solaris should have little trouble. IBM offers AIX training to some customers.

We ran Ziff Davis Media Inc.s NetBench 7.0 benchmark to measure server throughput for file read and write requests from clients. The p660 achieved a solid throughput of 395M bps.

Killer memory

the p660 boasts many redundancy features to ensure high availability for the applications it hosts, including redundant power supplies, fans, hot-pluggable hard drives and PCI slots, but most noteworthy are the ECC Chipkill memory and Dynamic Processor Deallocation.

In mission-critical applications such as ERP (enterprise resource planning) and CRM (customer relationship management), ECC alone is not enough to protect the server from memory error crashes because ECC detects and corrects only single-bit errors. Chipkill provides multibit error correction and detection that is transparent to the server and prevents crashes even when an entire memory chip fails. Because systems that implement Chipkill memory will be less likely to crash due to memory errors, this technology is usually employed on mainframes or on other systems hosting mission-critical apps.

The Dynamic Processor Deallocation feature works in conjunction with the AIX operating system to redistribute system workloads when one of the processors in the p660 indicates an imminent failure. The problematic processor is taken offline, and the system reallocates its workload to the other processors, minimizing system downtime.

An integrated service processor continuously monitors the servers vital signs and can be configured to send out an alert to an IBM service center when a malfunction occurs. IBM then sends a service technician to fix the problem at the customers site.

The p660 can easily scale to accommodate the needs of fast-growing enterprise infrastructures. The system has two memory riser cards, each with 16 DIMM (dual in-line memory module) slots for scaling the system with up to 32GB of memory using 1,024MB DIMMs. An additional I/O drawer can be added to expand the system with 28 hot-pluggable PCI slots.

IBM offers a specialized clustering solution where as many as 32 pSeries and RS/6000 AIX servers can participate in a cluster with IBMs Parallel System Support Programs.