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
179 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
179 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
179 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

iOS 19 Mock WWDC25 Feature

iOS 19 Expected to Run on These iPhones

Monday March 31, 2025 5:28 pm PDT by
iOS 19 will not be available on the iPhone XR, iPhone XS, or the iPhone XS Max, according a private account on social media site X that has accurately provided information on device compatibility in the past. The iPhone XR, iPhone XS, and iPhone XS Max all have an A12 Bionic chip, so it looks like iOS 19 will discontinue support for that chip. All other iPhones that run iOS 18 are expected...
maxresdefault

Apple Releases iOS 18.4 With Priority Notifications, Ambient Music, New Emoji and More

Monday March 31, 2025 10:03 am PDT by
Apple today released iOS 18.4 and iPadOS 18.4, the fourth major updates to the iOS 18 and iPadOS 18 operating system updates that came out last year. iOS 18.4 and iPadOS 18.4 come two months after Apple released iOS 18.3 and iPadOS 18.3. Subscribe to the MacRumors YouTube channel for more videos. The new software can be downloaded on eligible iPhones and iPads over-the-air by going to...
watchOS 11 Thumb 2 1

Apple Releases watchOS 11.4 With Sleep Alarm Update

Tuesday April 1, 2025 10:34 am PDT by
Apple today released watchOS 11.4, the fourth major update to the operating system that runs on the Apple Watch. watchOS 11.4 is compatible with the Apple Watch Series 6 and later, all Apple Watch Ultra models, and the Apple Watch SE 2. watchOS 11.4 can be downloaded on a connected iPhone by opening up the Apple Watch app and going to General > Software Update. To install the new software,...
AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 2 and AirPods 4

Monday March 31, 2025 11:27 am PDT by
Apple today released new firmware updates for all AirPods 4 and AirPods Pro 2 models. The new firmware is version 7E93, up from the 7B21 firmware that was installed on the AirPods Pro 2 and the 7B20 firmware available on the AirPods 4 and AirPods 4 with ANC. It is not immediately clear what new features or changes are included in the new firmware, but we'll update this article should we find ...
macOS Sequoia Feature

Apple Releases macOS Sequoia 15.4 With Mail Categorization and More

Monday March 31, 2025 10:04 am PDT by
Apple today released macOS Sequoia 15.4, the fourth major update to the macOS Sequoia operating system that launched in September. macOS Sequoia 15.4 comes two months after the launch of macOS Sequoia 15.3. Mac users can download the ‌‌macOS Sequoia‌‌ update through the Software Update section of System Settings. It is available for free on all Macs able to run macOS 15. With...
iPhone 17 Pro 34ths Perspective

iPhone 17 Pro Launching Later This Year With These 10 New Features

Sunday March 23, 2025 10:00 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 March 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 ...
Apple Card iPhone 16 Pro Feature

Visa and American Express Vying to Win Apple Card Deal in 'Fierce' Fight

Tuesday April 1, 2025 1:50 pm PDT by
Visa wants to pay Apple approximately $100 million to be the new payment network for the Apple Card, reports The Wall Street Journal. As of right now, the Apple Card is on the Mastercard payment network, but that is set to change because Apple is ending its partnership with Goldman Sachs. Both American Express and Visa are vying to replace Mastercard as Apple's card services provider, while...