The Mac OS is now OS X; OS X is Unix; and Unix is the fastest, stablest server platform around. With Mac OS X Server, Apple has made the benefits of a Unix server OS available via point and click. The only thing missing from this picture has been true server hardware on which to properly run this operating system–until Xserve. We gave the $3,999, dual-1GHz Xserve configuration a working-over and found that, while it lacks redundancy and has some design flaws, the advantages of so much G4 power in such a compact machine may make it worth your while.
Is the Xserve for You?
The Xserve is for anyone who wants to fit a lot of Mac in a little rack space–from small shops that want one powerful server tucked away in a phone closet, to video-effects houses that would benefit from putting 40 Xserves in a single cabinet. Depending on the configuration you choose, the Xserve packs as many as two 1GHz G4 processors, as much as 2GB of RAM, and as many as four 60GB or 120GB hard drives in an industry-standard 1U rack case (1.75 inches of vertical server-rack space–so you can fit more than 40 Xserves in a six-foot-tall rack).
The Xserve can also serve as a workstation in environments where equipment is often rack mounted, but keep in mind that the two 5,000-rpm blowers that cool the internal components make the Xserve much noisier than a G4 tower. Also note that it’s intended only for rack mounting: at 19 inches wide and 28 inches deep, it uses too much real estate on a counter or desk, and it’s not designed to support monitors or other components set on top of its case.
Out of the Box
Don’t be fooled by Apple’s photos of the slender Xserve, which are taken from the front of the unit. Viewed from above, it looks huge; its slight height is possible thanks to its generous 28-inch depth. The 26-pound Xserve’s dimensions are standard for a 1U server but still surprising the first time you see the unit.
The Xserve’s finish is similar to that of the Titanium PowerBook G4, with a solid look-and-feel. The case is rigid, so you can handle the server without twisting (and possibly unseating) cards and other internal components.
The back of the server features two FireWire, two USB, and two 10BaseT/100BaseT/1000BaseT (Gigabit) Ethernet ports, as well as a single video port. The power connection has a clever retainer clip designed to spare you the shame of a sudden inadvertent shutdown. The final touch is standard fare for Unix servers but new to the Mac: a console-redirection port that gives you command-line access over a serial cable.
Beneath a slim CD-ROM drive, four removable drive bays dominate the front panel. Pressing on the front of a drive bay causes it to pop open, spinning down the drive and revealing a handle with which to pull the module out. Lights indicating Ethernet link, processor activity, and drive status provide both valuable information and techie-gizmo appeal. An additional front-panel FireWire port gives the digital-media crowd a place to plug in without hiking to the back of the rack.
The system-identifier button is a brilliant feature for anyone with multiple Xserves in a stack. Pressing this button turns on amber LEDs on the front and back of the case, allowing you to tag a server from the front and then easily find it again from the back.
A twist of a key activates the locking system that prevents the case from being opened, secures the drive modules, and disables the CD-ROM drive. If a FireWire hard drive was mounted before the system was locked, it remains mounted while newly attached devices are ignored. Likewise, USB connections to an uninterruptible power supply remain, but keyboard and mouse connections are blocked. Unfortunately, the key is only an Allen wrench with a fancy knurled handle–the standard locked-door approach to physical security is still your best bet.
Into the Rack
The Xserve comes with hardware and instructions for mounting in four-post and two-post racks. In a two-post installation, it can’t be mounted flush against the front of the rack, so it must extend both in front of and behind the rack posts. The top and sides of the case form a light shell that you can slide off the server and mount in the rack. You then slide the server into the secured shell and lock it in with two thumbscrews. Mounting the 26-pound Xserve is a two-person job, and its flexible shell doesn’t properly prevent it from falling through the bottom until it is halfway in the shell. Furthermore, we recommend that you remove the Xserve completely from the rack to service internal components.
While mounting our test unit, we discovered a serious design flaw. When you’re handling or working around the Xserve, it’s very easy to bump the front of a drive bay, popping the handle out and disabling the hard drive. If you do this to the boot disk on a running Xserve, you get an instant system crash and possible data loss. The system lock doesn’t currently prevent this, but Apple is working on solving the problem.
Uptime Is Everything
If your desktop is down for an hour, you lose an hour of work. But if a server is offline for an hour, your entire company loses an hour of work. To provide maximum uptime, servers use monitoring and redundancy–the Xserve excels at the former and all but omits the latter.
By sensing and reporting hardware status, a server can warn a network administrator of potential problems, and the Xserve is full of sensors. It knows whether (and how fast) the fans are running. It knows how much power it’s using and how hot it is. It takes advantage of diagnostic chips on the hard drives to predict drive failures, and it monitors its network-connection status.
All of this vital information is reported via the well-designed Server Monitor, a remote-management application that works only with the Xserve. Server Monitor can be set up to notify you of problems via e-mail, so warnings will also reach your e-mailenabled cell phone or pager. Remote management is enabled via an extensive suite of graphical, command-line, and SNMP remote-management tools. In addition, if you can’t respond to a temperature warning, the Xserve should shut itself off before overheating causes it to fail.
Unfortunately, the Xserve lacks redundant fans or power supplies, and it lets you create redundant hard drives only via the feature-poor and unreliable software-RAID implementation included in Apple’s Disk Utility. When we tested our Xserve with two 60GB drives formatted as a mirrored array, Disk Utility didn’t let us mirror a drive on which we already had data, forcing us to erase all drives in the RAID set and start over. (Our advice is to decide on your setup before you begin to configure your server.)
When we removed a drive canister to simulate a failure, the Xserve ran without interruption, although it failed to alert us that a drive had been removed or that the RAID set was broken. We also experienced serious difficulty in rebuilding the mirrored drive. As with any system you rely on in a crisis, you should test failure and recovery behavior yourself, before the server is in production. For now, if you need the dataloss insurance provided by redundant hard drives, we recommend that you use an external hardware RAID.
If a component does fail, the Xserve can be quickly serviced with the optional spare-parts kit, but at $1,549 to $2,509, it’s best suited for installations with multiple Xserves. Apple also offers AppleCare Premium Support for both the Xserve hardware and your OS X Server software, at $950 for three years of around-the-clock phone and e-mail support with 4-hour or next-day on-site service.
Macworld’s Buying Advice
The Xserve packs intense G4 processing power in a small form factor, so if your setup demands server-side processing, the Xserve is for you. As a storage server, the Xserve delivers mixed results. With as much as 480GB of drive space, there’s plenty of capacity, but the current lack of reliable on-board RAID limits the Xserve’s use to applications where uptime and data-loss protection aren’t of primary importance, or environments that utilize external redundant storage.