For a number of months my beloved MacBook has been suffering from frequent hangs and crashes. I initially ignored it, thinking that I was simply pushing the machine to the edges of its capabilities. But in the back of my mind I knew better - Macs are more than capable of keeping up. Eventually, I added an item to my to do list - troubleshoot MacBook.
I started my troubleshooting efforts by identifying possible third party programs that could have been the culprit. I quickly honed in on a Blackberry application which I seldom used. I uninstalled it, but my woes continued. I resorted to checking error logs, but found nothing telltale. I continued to bare with the problem.
The more I tried to put up with the problem, the worse it seemed. One by one applications would become unresponsive, eventually hanging up the entire operating system. Sometimes I'd leave my machine and come back to find that it crashed and rebooted. Enough was enough! The problem had to be found and remedied. And I prayed that it wasn't a hardware issue.
I finally had a breakthrough when one of the forced reboots took place while I was using the machine. When my poor MacBook rebooted, it kindly asked if it could phone home - a prompt was presented asking my permission to submit a bit report to Apple. I decided to look at what it was going to submit. At this point the heavens opened up and the angels sang! Within the error report I noticed the following important tidbit:
Kernel Extensions in backtrace:com.sophos.kext.sav...
And there it was, the source of my problem. That line of text identified the source of the problem as Sophos Antivirus for Mac Home Edition. Why am I running an antivirus on a Mac? Because no system is bullet proof. But let's not digress. I started researching the issue and discovered that Sophos antivirus had indeed been linked to crashing Macs. Specifically, during virus database updates (which are done hourly by default) the scan on file access feature stops processing requests. Therefore, when applications need to access the hard drive, they hang while waiting for Sophos to allow access to the file requested. Except Sophos never grants said access. This continues until every application, including the operating system is frozen waiting to access the hard drive.
I was overjoyed to have finally found the source of the problem. I was also thoroughly annoyed that something which was meant to protect my computer was in fact harming it. I could simply have turned off the offending scan on access feature, but months of frustration demanded vengeance. Delete!
I am now running my Mac without an antivirus. Unlike my Windows using brethren, I can still get away with this.