Since the release of Mac OS X 10.6.8 last week, a number of Xserve users have reported in Apple's discussion forums (via MacNN) issues with a hardware monitoring daemon known as hwmond generating significant CPU loads of up to 95%.

Member Arminhempel reports a CPU load up to 70 percent after every reboot on several Xserves he manages; Jean-Serge Remy has an Xserve Xeon showing an 84 percent hit, while InfraredAD is experiencing a 95 percent load on a 2008 quad-core Xserve, essentially wiping out an entire core. Both the combo and delta versions of the update have generated errors and, so far, the only reliable way to fix the issue is a downgrade to Mac OS X 10.6.7.

The update also appears to be causing occasional issues with shutdowns and restarts as users attempt to address the hwmond CPU load issue.

xserve box
Apple has yet to offer a specific solution for the issue, merely walking users who have contacted Apple Support through some troubleshooting steps without a specific resolution in place. But given the volume of complaints appearing in discussion forums, Apple will likely have to release a patch to address the issue.

Top Rated Comments

ouimetnick Avatar
180 months ago
How does Apple screw something like an Xserve up? I mean this is a BUSINESS class product, and if there is nothing wrong with it, don't fix it!
Score: 3 Votes (Like | Disagree)
peskaa Avatar
180 months ago
It really isn't worth rolling back over, there is a simple workaround: -

Kill until reboot: -

sudo launchctl unload /System/Library/LaunchDaemons/com.apple.hwmond.plist

Kill permanently: -
sudo launchctl unload /System/Library/LaunchDaemons/com.apple.hwmond.plist
sudo mv /System/Library/LaunchDaemons/com.apple.hwmond.plist ~/Desktop/

The only thing I have noticed since doing this is the cpu-load leds on the front of our xserves stay fixed where they were the moment hwmond was killed, not a biggie.

HTH

Is it also killing the load monitors elsewhere? We do remote monitoring as the racks are tucked out of sight in a locked room. I rolled the one test bed back to 10.6.7 this morning though, finally had time to do it. Also found one of the Xserve RAIDs had had a minor HD meltdown as well...

If it's just LEDs, then I can live with that.
Score: 1 Votes (Like | Disagree)
codeus Avatar
180 months ago
Yeah, it won't die permanently. Rolling back to .7 is the only solution until it gets fixed.

It really isn't worth rolling back over, there is a simple workaround: -

Kill until reboot: -

sudo launchctl unload /System/Library/LaunchDaemons/com.apple.hwmond.plist

Kill permanently: -
sudo launchctl unload /System/Library/LaunchDaemons/com.apple.hwmond.plist
sudo mv /System/Library/LaunchDaemons/com.apple.hwmond.plist ~/Desktop/

The only thing I have noticed since doing this is the cpu-load leds on the front of our xserves stay fixed where they were the moment hwmond was killed, not a biggie.

HTH
Score: 1 Votes (Like | Disagree)
MvdM Avatar
180 months ago
How does Apple screw something like an Xserve up? I mean this is a BUSINESS class product, and if there is nothing wrong with it, don't fix it!

Probably the same way as how they screw all their other business class products (Final Cut Pro, Cinema Displays, glossy Macbook Pros).
Score: 1 Votes (Like | Disagree)
markfrautschi Avatar
180 months ago
Parallels update ParallelsDesktop-parallels-en_US-6.0.12092.670880 may help

My 2007 MacPro(1,1) 4-core runs Mac OS X 10.6.8 client, not server, and was having problems with the Parallels VM (prl_vm) task swamping two cores which was accompanied by the Parallels Desktop v6 app becoming unresponsive. (I did not notice these problems under Mac OS X 10.6.7) Coincidently Parallels Desktop for Mac update US-6.0.12092.670880 was released, which appears to have solved the problem in my case. Perhaps this is related to the XServe issue reported in this thread and an update to Parallels there will help.


Parallels is a well known, widely used app - if they broke it in a maintenance update Apple's QA must be piss poor, bare minimum.

I have a similar problem since I upgraded. Did some searching this morning and found out it is related to Parallels. Obviously this isn't what everyone is experiencing, but if you have Parallels, there is a workaround here
http://kb.parallels.com/en/111541
Score: 1 Votes (Like | Disagree)
ratsg Avatar
180 months ago
Correct, it is recently discontinued, but it is still supported.

It is a DISCONTINUED business class product. And one that Apple never used themselves in their own data centers - they always used Sun hardware and Sun Solaris. The fact that they never ate their own dog food tells you a lot about how committed Apple are to their own business class products.
Score: 1 Votes (Like | Disagree)

Popular Stories

AirPods Pro 3 Mock Feature

AirPods Pro 3 Just Months Away – Here's What We Know

Friday April 18, 2025 5:16 am PDT by
Despite being more than two years old, Apple's AirPods Pro 2 still dominate the premium wireless‑earbud space, thanks to a potent mix of top‑tier audio, class‑leading noise cancellation, and Apple's habit of delivering major new features through software updates. With AirPods Pro 3 widely expected to arrive in 2025, prospective buyers now face a familiar dilemma: snap up the proven...
iphone 17 air dummy unbox therapy

iPhone 17 Air's Extreme Thinness Demoed in New Video

Tuesday April 22, 2025 10:22 am PDT by
Apple plans to release an all-new super thin iPhone this year, debuting it alongside the iPhone 17, iPhone 17 Pro, and iPhone 17 Pro Max. We've seen pictures of dummy models, cases, and renders with the design, but Lewis Hilsenteger of Unbox Therapy today showed off newer dummy models that give us a better idea of just how thin the "iPhone 17 Air" will be. The iPhone 17 Air is expected to be ...
iphone 17 dummies sonny dickson

iPhone 17 Air Almost as Thin as Its Buttons, New Images Show

Thursday April 24, 2025 2:14 am PDT by
If you missed the video showing dummy models of Apple's all-new super thin iPhone 17 Air that's expected later this year, Sonny Dickson this morning shared some further images of the device in close alignment with the other dummy models in the iPhone 17 lineup, indicating just how thin it is likely to be in comparison. The iPhone 17 Air is expected to be around 5.5mm thick – with a thicker ...
ipad air windows 11 arm

M2 iPad Air Runs Windows 11 ARM via Emulation, Thanks to EU Rules

Tuesday April 22, 2025 5:01 am PDT by
A developer has demonstrated Windows 11 ARM running on an M2 iPad Air using emulation, which has become much easier since the EU's Digital Markets Act (DMA) regulations came into effect. As spotted by Windows Latest, NTDev shared an instance of the emulation on social media and posted a video on YouTube (embedded below) demonstrating it in action. The achievement relies on new EU regulatory...
iphone 16 pro models 1

17 Reasons to Wait for the iPhone 17

Thursday April 17, 2025 4:12 am PDT by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models simultaneously, which is why we often get rumored features months ahead of launch. The iPhone 17 series is no different, and we already have a good idea of what to expect from Apple's 2025 smartphone lineup. If you skipped the iPhone...
iOS 18

iOS 18.5 Includes Only a Few Changes So Far

Monday April 21, 2025 11:00 am PDT by
Apple seeded the third beta of iOS 18.5 to developers today, and so far the software update includes only a few minor changes. The changes are in the Mail and Settings apps. In the Mail app, you can now easily turn off contact photos directly within the app, by tapping on the circle with three dots in the top-right corner. In the Settings app, AppleCare+ coverage information is more...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching Later This Year With These 13 New Features

Wednesday April 23, 2025 8:31 am PDT by
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of April 2025: Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone ...