Volume Number: 26
Issue Number: 01
Column Tag: Xserve, Hardware

Reducing Xserve Fan Speeds

Forgotten maintenance increases wear on your server

by Neil Ticktin, Editor-in-Chief

If you have an Xserve, you likely have checked out the Server Monitor utility. Among other things, Server Monitor shows the fan speeds for the assortment of fans that is in each Xserve model. Over time, you've likely seen these fan speeds increase. You may be concerned about the server overheating especially during an unexpected surge of traffic or use.

All the Xserves have two air intake ports. At the back, there are two grilles about 8" back from the front of the machine (which makes it difficult to see unless you are looking at them straight on. Most Xserves are so low maintenance and trouble free, you may forget about cleaning these grilles.

Over time, if you don't clean these grilles, you'll see fan speeds increase, and if you let it go long enough, you may even see some of your fans running so fast that the Xserve generates warnings or even shut down.

In our real life example, fan speeds on this Xserve were regularly over 10,000 rpm for at least one of the fans. As you can see from the before and after photos, enough dust had accumulated (even in a relatively clean room) that it was difficult for air to move through the grill. After cleaning, however, it was easy, and fan speeds dropped by 2,000-4,000 rpm by doing nothing more than cleaning these grilles.

These grilles are difficult to see and work with because they are so far back from the front.  That said, because it's a narrow tube, they are particularly easy to vacuum out (e.g., the vacuum is able to suck the grille clean in the enclosed area). It's important here to not push the dust through the grilles and into the heart of the Xserve, but instead, remove the dust. This can be done with a simple vacuum attachment like a flat crevice tool, or wand, to reach most of the way down the intake port. It's amazing how fast and easy the dust vacuums out. It should go without saying that it's best to do the cleaning with the Xserve powered down.

You should periodically (monthly or quarterly) inspect the intake ports for dust and clean accordingly. Doing so will not only make your Xserve run cooler, but with less effort.

Before Cleaning: Grille at Back of Xserve Air Intake Port

After Cleaning: Same Air Intake Port

Neil Ticktin is the Editor-in-Chief and Publisher of MacTech Magazine. Neil has been in the Mac industry since 1985 and has developed software, written documentation, and been heading up the magazine since 1992. When Neil writes an article, he likes to focus on it from the most real world point of view. Drop him a line at publisher@mactech.com