hwmond high cpu load after 10.6.8 update

Same Problem here. I will only update one server at this point. Hard to believe this did not get checked by Apple.

Same problem on Xserve3,1 with Combo Update.

does anyone have any feedback from Apple techs on this? I am waiting to update. Will wait a another week or so to make sure any issues are worked out.

Thanks,

Nothing yet on my end, I filed a bug report on June 24, no love.

In response to BCarneal's message above, Re: hwmond high cpu load after 10.6.8 update, I copied the stock plist back and loaded hwmond via launchctl last night, it's back to 94%, my processor LED's are functioning now, and I plan to leave it running for about 2 1/2 days to see if it settles down on its own. Higher math skills tell me he let his be for about 2 days, 5 hours(?). Maybe it's actually doing something, but what, who knows, because my logs aren't being spammed.

Called Apple no help. Wants me to zap NVRAM. I cannot do that until tomorrow AM. 😟

Also having problems with an Xserve 3,1 after applying the 10.6.8 delta update from 10.6.7. Filed a bug report with Apple

Thanks to InfraredAD for the tip on disabling hwmond at startup!

Hi Guys,

I too had the same problem.. Luckily it was for a server that isn't due to come into service until the weekend. Having zapped the PRAM I can confirm that HWMOND has gone from 86% down to 0.4 - 1.3% CPU.

This is on a 2009 Qcore 2.26 Xserve which had 10.6 server installed and the combo update to 10.6.8 added.

I also updated one of our other servers from 10.6.7 to 10.6.8 with the Delta update and that's working fine. Xserve 1.1 2x2GHZ.

Hope that helps some of you.

Beatle

I hate to say me too, but alas,

Me too...

Xserve 2,1 Updated via SU.

I'll reset the NVRAM and report back.

oh and thanks to Appleinsider for picking this up. I'd noticed that we had higher CPU usage than normal but had not looked further into it.

and Thanks to all of you for some good ideas .

This worked for me on two different Xserve3,1 systems which had the same problem following the combo upgrade to 10.6.8 (I had no problems with two Macmini3,1 systems which were updated at the same time).

Step 1 (terminal): sudo hwmond -s250 (sets the update frequency to 250 seconds) this will give the error message identified by arminhempel.

Step 2 (activity monitor) you will now see 2 threads for hwmond, both with high CPU utilization; kill each one (using force quit)

Both of my Xserves spawned a new hwmond process which consumed about 0.4% CPU for the thread.

Both systems have now been running for 24 hours with no excess CPU utilization for hwmond.

Apparently, the update frequency sticks even after the error message, but doesn't take effect until a new process is spawned.

Also having the issue here on an XServe 2,1 updated via the combo update. Didn't even notice until I saw this story pop up on macrumors. Since this server has a pretty minimal load it doesn't really affect me other than higher electricity useage I suppose, but for what it's worth, the hwmond -s trick didn't work.

Things I have tried on my xserve1,1 dual dual 2.0 intel:

Install delta 10.6.8 (start of the problem)

Install combo update 10.6.8 (problem persists)

zap pram 5 times (problem persists)

modify the com.apple.hwmond.plist to add -s 250 to the arguments (problem persists)

My current work around is:

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

(unload that persists accross reboots, change unload to load to re-enable)

The one thing I have not tried that just occured to me is to try removing my usb -> ps2 adaptor for the KVM, in case that is some how causing an issue. Pulling the non OS drives (I do think one of the drives is a non apple drive that was replaced in an ADM, but I inhereted this server from another group). Otherwise, this xserve is pretty much bone stock. I may try these things later when I get a chance.

Perhaps people should list off if they are using any peripherals or ADMs with non apple replacement disks in them (hwmond does after all monitor the status of various things such as these), it would be interesting to see if some correlation forms.

Good luck, have fun, let me know if someone finds a work around that works AND hwmond can run.

Xserve 2,1 stock, 2- 3Ghz Xeon 32 Gb Ram Raid 5

The "sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.hwmond.plist"

worked for me. not noticed any oddities. We use it to run Parallels VMs hosting Windows, and the VMs started up.

I want to make it perfectly clear that what I stated DISABLES hwmond, this will mean your server monitor will no longer update all the fields that update when the machine is running, but eveyrthing that works in the LOM will continue to work when the machine is off. Server Admin may also have some values that do not update, I have not yet checked.

The important thing is that I'm back from a 3 core xserve, to a 4 core.

Same thing on an Xserve3,1. Very frustrating.