Recently, I’ve been experiencing a high CPU usage by the process syslogd in Mac OS X 10.5.2 Leopard, coupled with strange Console.app behavior. If you’re experiencing this as well, give this a shot and see if it works (at your own risk.)
FIrst, you should check if this is a problem on your system, which is usually caused by large asl.db files. Open Terminal.app (Applications/Utilities/Terminal.app) and enter the following:
du -hs /var/log/asl.db
and hit enter. If it shows that your asl.db file is pretty huge (mine was 80MB) you’ll want to run this fix. If it isn’t, a rampant syslogd is probably not due to the asl.db file, but instead some application doing a lot of logging. Open Console and look if there’s any applications that are logging a lot, like if you see “ — last message repeated 500 times —”, that’s probably what is causing syslogd to own a lot of CPU.
If asl.db is huge, do the following. You’ll first have to enable a root user to your system. Then, go to Terminal, and enter the following (enter one by one, and hit enter afterwards):
sudo launchctl stop com.apple.syslogd
sudo mv /var/log/asl.db /var/log/aslold.db
sudo touch /var/log/asl.db
sudo launchctl start com.apple.syslogd
You will be asked to enter the root password on the first command, while subsequent commands will automatically be authenticated as root.
Once you do this, the syslogd process should restart, but the CPU it uses should be next to nothing. Hope this helped.
THANK YOU!!!! I have been looking for a solution to the problem all night. Some didn’t work and others were way above my knowledge. My computer has been so slow and this totally took care of it. Honestly, THANK YOU SO MUCH!!!
Thank you! That worked great!
This worked perfectly!
Thank you! Same problem like you and same solution applied. Now everything’s working well!
Yet another big thank you! Fan shut down seconds after moving the gigantic file.
This just fixed my runaway syslogd process! I have been killing the process for months, trying seeing nothing in the logs. This seems to have fixed it, BTW, my asl.db was 373M.
thanks for the tip.
The same works for many other haywire root software problems, as well as renegade 3rd party issues.
Thanks, fix worked perfect.
macbook:~ martin$ sudo file /var/log/asl.db
/var/log/asl.db: data
I’m guessing that means it’s either corrupt, or just shows that using massive binary blobs is a bad idea. I was using Instruments to debug some C code on 10.5.5, so I figure that might have pushed it.
[...] Follow this link: The Mark Bao Weblog. » Mac OS X: Fix High CPU Usage by syslogd [...]
I also suffer from horrible cpu spikes caused by timemachine .. oddly enough I dont even have the above mentioned file.
I’m not 100% sure of this, but I believe you do NOT need to enable the root user to make this work. And if you don’t have to, you shouldn’t. Enabling root is dangerous from a security perspective. You can still execute commands as root by doing exactly what this tutorial says: precede each command with ‘sudo’. So, for example, sudo launchctl stop com.apple.syslogd means “execute launchctl stop com.apple.syslogd as root.” You will have to do it when logged into Terminal as an administrative user of your box. If you have only one user on your Mac OS X box that user is an admin user.
I have several users on my Mac OS X box. I do not run my admin user unless I need to for administrative, maintenance or troubleshooting purposes. I am able to execute sudo commands simply by opening a terminal window and logging in to that terminal session as my admin user. And I do **not** have root enabled.
[...] syslogd uses up excessive CPU time. Thankfully, there’s a reasonably straightforward fix on The Mark Bao Weblog for those who are reasonably au fait with the OS X Terminal, and it certainly solved the problem [...]