Most organizations aspire to high availability. However, high availability typically comes at the cost of implementing highly complex and difficult to manage solutions, such as Microsoft’s failover clustering. Stratus Technologies’s Stratus ftServer 4500 is a high-availability server that can provide five 9’s of availability with very little added complexity. Much like the NEC 5800 unit that I reviewed earlier this year (see “NEC Express5800/R320”), the Stratus ftServer 4500 is a 4U rack-mounted server that provides dual copies of all system components. In other words, there are two motherboards, two sets of CPUs, and two sets of RAM and storage. Each of these sets is contained in its own 2U unit. Stratus calls each unit a CPU-I/O Enclosure. Each of these CPU-I/O Enclosures slides into a shared rack-mounted chassis. The two CPU units run in lockstep, with the current memory and CPU instructions shared between each of the two CPU-I/O Enclosures. Figure 1 shows the Stratus ftServer 4500.
Figure 1: Stratus ftServer 4500
From when I first opened the shipping container, it was apparent that the Stratus ftServer is in a league apart from ordinary servers. Instead of arriving in a plain corrugated box, the Stratus 4500 arrived on a palette. The Stratus ftServer shipped in three main pieces: two CPU-I/O Enclosures and one industrial-strength steel chassis. These components were quite heavy, so the ftServer installation took a little doing. To install the unit, I first installed the chassis into my server rack and then slid each of the CPU-I/O Enclosures into the chassis. I used thumbscrews at the front the unit to secure the CPU-I/O Enclosures. The chassis provides internal connectors that are used to plug in each CPU-I/O Enclosure. These connectors are how the CPU-I/O Enclosures communicate and stay in sync.
The Stratus ftServer 4500 that I tested came equipped with two logical Intel Xeon E5504 quad-core CPUs running at 2GHz. The system also made use of the Intel 5500 chipset. The unit that I tested came configured with 16GB of RAM and 136GB of Serial Attached SCSI (SAS) disk storage spinning at 15K rpm. In the case of this system, the key word is logical because the ftServer actually has two physically matching sets of CPU, motherboard, RAM, and disk storage—one set per CPU-I/O Enclosure. This duplication of system components is what enables the fault tolerance. Each CPU-I/O Enclosure can support up to 96GB of RAM running at 800MHz and up to 4.8TB of SAS disk storage.
Internally, each CPI-I/O Enclosure had two PCI Express 2.0 expansion slots and four more optional PCI Express 1.0 or PCI-X expansion slots. On the back of each CPU-I/O Enclosure, there were three 1GB network ports. Two of the network adapters were intended for client networking activity, whereas the other network adapter was reserved for remote management. In addition, each CPU-I/O Enclosure also had an additional two-port 1GB network adapter. Between both of the CPU-I/O Enclosures, there were eight client network ports, which were configured as a team using Intel’s Advanced Network Services (ANS) technology. This teaming technology provides networking fault tolerance.
Each CPI-I/O Enclosure in my test unit also had a Fibre Channel adapter. The connections for the video display, keyboard, serial ports, and USB ports were on the chassis—not on each CPU-I/O Enclosure. The video used a standard nine-pin VGA port. An integrated video controller provided 8MB of RAM and supported a maximum of 1024 ´ 768 display resolution. Notably, the Stratus ftServer 4500 had no PS/2-style mouse and keyboard ports. The mouse and keyboard connections are USB only; you can use the port on the front of the unit or the three USB ports on the back of the unit. Because two of these ports are required by the mouse and keyboard, I wished the unit had more USB ports available—especially on the front of the system. The front of the chassis also provided a vertically mounted DVD-RW drive.
The Stratus ftServer 4500 that I tested came with Windows Server 2008 R2 x64 Enterprise Edition preinstalled. You can also order it with VMware vSphere 4 or Red Hat Enterprise Linux (RHEL) 5.