Xserve

Originally announced in August, Apple’s fifth-generation Xserve began shipping to customers in November. Now powered by Intel processors and bursting with contemporary technologies, Apple’s server straddles the disparate requirements of a data-center-friendly server while still being a user-friendly Mac. The result is a high-performance Mac server that brings a few compromises along for the ride.

The Xserve’s base configuration offers two dual-core 2GHz Xeon processors, 1GB of 667MHz DDR2 memory, and an 80GB, 7200-rpm SATA disk, all in a 1U enclosure for $2,999. There are also two eight-lane PCI Express slots (one can be configured for a PCI-X card), dual onboard Gigabit Ethernet, and a combo drive. The Xserve also features dual FireWire 800 ports, one FireWire 400 port, two USB 2.0 ports, and a DB-9 serial port. Other available options include 2.66GHz or 3GHz processors, up to 32GB of RAM in eight DIMM slots, a second power supply, and an assortment of video, Fibre Channel and SCSI controllers. The Xserve accommodates three 3.5-inch hard disks, and you now can mix and match either 7,200-rpm SATA or 15,000-rpm Serial SCSI (SAS) disks. As before, an unlimited-client version of Mac OS X Server is also included with each Xserve. For this review, Apple provided an Xserve with 3GHz processors, four 1GB FB-DIMMs, three 750GB SATA disks, a SuperDrive, dual power supplies, and a Fiber Channel card. The final price for this configuration is $8,571.

Nuts and bolts

The new Xserve installs easily into a rack. Thankfully, Apple has replaced the old (and fragile) lid-and-rails combination with a traditional rail assembly. There are separate rail kits for racks with square or round holes—make sure you order the correct one. (Apple says it will swap the rail kit if you make a mistake, but better safe than sorry.) If your rack has square holes, you can celebrate and discard those annoying retainer nuts. Apple’s rails attach from behind the posts and mate with a front-mounting spacer; the spacer’s square dimple matches exactly with the rack’s square hole. Just prop up the rails, slide on the spacer, and screw it down—everything aligns all at once. The server easily notches into the rails, and the Teflon coating ensures a smooth, easy slide into the rack.

The new Xserve retains the basic look and functionality of its predecessors. It boots from disk, CD, network, or into FireWire Target Mode, as expected. The familiar front panel has the same key lock, buttons, status lights, and FireWire 400 port. The very slick Apple Drive Modules remain the same, and the handles still pop out at the slightest touch. The sixteen processor indicator lights now reflect activity in the Xserve’s four processor cores, with four lights available to each core.

The server’s default configuration includes an optional ATI Radeon X1300 video controller with 64MB of dedicated SDRAM. The video card does not occupy one of the two PCI-Express slots, but instead mounts on a mezzanine card. The video jack is now a mini-DVI connector; Apple includes adapters for VGA and DVI displays. The VGA adapter worked with my Raritan KVM, but I got a secure connection only after carefully positioning the adapter; I would have preferred a traditional VGA connector on the server. (Folks doing video or visualization will appreciate the DVI option.)

The new Xserve’s cooling systems are impressive. Variable-speed fans drive cool air to each of the power supplies, processors, and RAM, and Apple uses copper heat sinks on the processors. Computer internals heat up under load, and this attention to cooling ensures maximum performance despite the thermal output.

Alas, in keeping the previous Xserve’s visual design, Apple missed a couple of opportunities to make everyday operation more convenient. For example, many other vendors now include video and USB ports on the front of their servers—for booting off a USB key, or those occasions when only a real monitor and keyboard will suffice. Xserve has these ports only on the back, which means you have to work amidst the cables, noise, and hot exhaust of a rack’s back. Similarly, it would have been nice if the new asset management tag (which lists the serial number and MAC addresses) were accessible from the front. The Xserve still must be removed from the rack before you can access its internals.

Unlike the Xserve G5, this version does not offer an option for hardware RAID. Given that RAID controllers are available from nearly any other server vendor—and are often located on the motherboard—this is a mind-numbing omission. Mac OS X’s software RAID is notoriously finicky and slower, and the Xserve G5’s optional RAID card was a welcome addition to any deployment requiring data redundancy. I hope that a RAID option will be available in the future, but until then customers must look to external storage alternatives.

Remote management

The Xserve and Mac OS X Server have always been strong on remote management, but this time Apple ups the ante with complete Lights-Out Management (LOM). This means you can remotely monitor, manage, and power the server up or down—even if it has suffered a kernel panic or is hidden in a far-away data center. Apple has implemented version 2.0 of the Intelligent Platform Management Interface (IPMI) specification; so long as the server has power and a network cable (and you can access the correct IP subnet), you can access the hardware’s internal systems with IPMI-compliant tools. In fact, Apple’s Server Monitor now requires IPMI access in order to manage Xeon Xserves.

Lights-Out Management sounds great, and works well once successfully configured, but Apple’s implementation is problematic. While the Xserve has two Ethernet ports, it has four network controllers; each port answers to two controllers, one for LOM and one for the server’s usual Ethernet network. Best practices call for LOM to be on a private, secure IP network, so you have to either dedicate one physical port to the LOM processor or embed complicated (and possibly unwanted) IP subnetting and access controls into the network layer. (Other vendors typically use a dedicated card with its own Ethernet port.) Where most LOM controllers come configured for DHCP or private RFC1918 address space, Apple’s ships completely unconfigured. (Apple says it chose a more secure out-of-box configuration for the initial release.) You must manually power up the server and use Server Assistant to configure the LOM processor. Even then, however, I couldn’t reliably access the LOM processor until I powered the server off (another trip to the rack), removed the power cables and then restored power, as documented on Apple’s Web site.

The Xserve’s installation DVD includes new versions of the server management utilities, and they are required for remote access via LOM. Apple also includes the command line IPMItool , a popular open-source utility. When booted off the DVD, you can now remotely control the Xserve with a VNC (Virtual Network Computing) viewer such as Apple Remote Desktop (   ).

How fast, exactly?

Benchmarks and performance tests are a tricky business, because the only performance that matters to you is that of your applications. Apple offers a number of benchmark scores to prove Xserve’s performance claims--both on the product’s Web page and in a recent Webcast to university and IT customers. But like all benchmarks, they should be carefully evaluated.

For example, Apple’s Web site touts the 3GHz Xeon Xserve as “up to 5 times faster” than a 2.3GHz Xserve G5; that number is based on the hardware’s score in the popular SPEC CPU2000 test of integer performance. However, Apple cites only scores in the tests that evaluate a system’s use of multiple processors. (The Xserve’s scores are in line with other systems using the 3GHz Xeon 5160.) With four cores against the G5’s two, a faster clock speed and memory bus, and Intel’s traditional strength in integer calculations, the results are not surprising. Not all applications use multiple processors effectively, however, and we notice that scores for the single-processor test are not provided. Moreover, scores for the Xserve G5 are based on Apple’s internal tests, and are not published on the SPEC Web site. This isn’t to say that the Xeon Xserve isn’t fast (it is), or that Apple’s claims are specious--only that Apple is being choosy about which benchmarks it publishes.

In Macworld ’s tests, the new Xserve is undoubtedly faster than an Xserve G5 currently deployed as an FTP and AFP (Apple Filing Protocol) file server. I compared the two on a private Gigabit Ethernet connection, using a Power Mac G5 as the client. The Xserve ran multiple trials, with one disk and with three disks in a software RAID 0 array, while the Xserve G5 had three disks in a hardware RAID 5 array; both systems used SATA disks. Downloading via FTP, the Xeon Xserve pushed data at 110MBps, nearly double that of the Xserve G5. The new Xserve also wins the AFP tests, in margins ranging from 30 percent to 60 percent. In most AFP tests, the Xserve was less than 10 percent faster with striped disks than with a single disk, and in one case the software RAID 0 was slower than a single disk. In the file duplication test, the Xserve’s striped disk configuration finished in a third of the time as the others. When I installed the Wireshark packet sniffer with Fink, the compile and installation were startlingly fast.

Customers are already submitting Xbench scores; I urge you to visit the Xbench database and evaluate with your applications in mind.

Macworld’s buying advice

Apple's Xserve is the very model of a modern Intel-based 1U server, with a few caveats. Configuration of the LOM needs to be refined, and the lack of a hardware RAID is a glaring omission. Most annoyances of past Xserves have been rectified, and the whole system ranks admirably among the finest available today. Before upgrading, make sure your applications and third-party devices are ready for an Intel-based Mac server.

[ Andrew T. Laurence is a server administrator and “Mac guy” at the University of California, Irvine. ]

Xserve’s new rails use the middle screw post to perch on the post’s square holes; nuts are welded to the back of the rail bracket.The Server Assistant has a new check box for configuring Lights-Out Management.Channel 1 and Channel 2 refer to the LOM controller that piggybacks on the similarly numbered Ethernet ports. The administrator account in this configuration is isolated to LOM and does not appear in Workgroup Manager; additional LOM accounts can be added in Server Monitor.

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