Lately, I’ve had a very rocky relationship with my Mac Book Pro. One
of the things that attracted me to OS X was its stability. Over the
past several months (before and after Leopard) my MBP has had trouble with
sleeping, waking, and weird, inexplicable freezing. Often when the
machine woke up, it would the screen would be black and never come
back. The machine would freeze at odd times and nothing would
unstick it. I couldn’t even log in remotely using SSH, so it was
pretty stuck.
The final straw was erratic mouse behavior. The mouse seemed
sluggish and wouldn’t follow the track. Only a reboot would cure it
and the it would deteriorate over the next 5-10 hours.
I considered an OS reload, but didn’t really expect that would solve
the problem since these issues had persisted through reloads before.
I suspected, but didn’t have much evidence that it has something to
do with a kernel extension because the locking up was occurring at a
deep level.
The good news is that OS X some new tools for exploring what kernel
extensions are loaded. I used the following command to see what
(besides Apple extensions) were loaded:
kextfind -loaded -not -bundle-id -substring 'com.apple' -print
Doing so revealed about five extensions. I started Google each one
and discovered that vmmain.kext was suspected in at least
one other case of causing erratic mouse behavior. I didn’t want
to uninstall Parallels to test this, so I just renamed the plist file
in StartupItems so it wouldn’t load.
mv /Library/StartupItems/Parallels/StartupParameters.plist foo.plist
Now, after a reboot, Parallels doesn’t load and looking at the loaded
kernel extensions shows that in particular vmmain.kext
hasn’t loaded.
I did this five days ago and my machine has been remarkably stable.
It feels like my old Mac again. I don’t know that it’s a Parallels
problem–at least not exclusively. I suspect that its an interaction
with other things. In particular, I run Parallels and Fusion both
and there may be some weird interaction going on there.
I like Parallels. I like Coherence better than Unity. I like the
snapshot feature in Parallels because it allows multiple snapshots of
the same image. But I need Fusion for running Fedora (Parallels
didn’t work so well for me there). Fusion also wins on the
performance front–particularly with multiple cores.
There are ways to load and unload kernel extensions and that may be a
better solution, but for now, I’m just using Fusion to see what
happens. I’ll let you know if my experiment turns up anything else.
