Why are the crash logs disappearing

logs

My mid-2010 MacBook Pro was diagnosed with the infamous nVidia graphics card defect (I went to an AppleStore two weeks ago, they ran the video system test, and it failed), and since it manifested later than 3 years after purchase, I do not qualify for the free logic board replacement. Still, I'd like this computer to last one more year, and since I get a crash every two weeks or so, it's viable. However, I'd like to make sure that the problem doesn't get worse, and for that I'd like to use the panic logs to monitor the frequency.

Which brings me to my problem: my crash logs seem to be disappearing (all my crash logs, though I really only care about panic logs). I noticed first when I went to the AppleStore for the first time that even though the computer crashed twice in the month and a few times before, only the most recent panic log remained. It just crashed again today and the two panic logs I had have vanished in favor of the last one.

Where are my crash logs going? Is there a setting I can use to keep them longer? Do I have to copy them over to a "safe" location to keep track of them? They are not backed up with Time Machine.

Best Answer

System logs, for example, are compressed and then automatically deleted after a week. However, System Diagnostic Reports (whether it be a stall, spin, hang, crash, or panic report) shouldn't be automatically deleted. If you reset the NVRAM immediately following a kernel panic, however, the report is deleted (the NVRAM temporarily stores the report until reboot; if it's reset, the contents are erased). Short of forcibly removing the files (using Onyx, a similar app, or manually), this is the only situation I can come up with off hand as to why a report would vanish.

As a makeshift solution, however, you can save the kernel panic reports as a separate file.

  1. From Console's menu bar, View > Show Log List
  2. Select the panic report (kernel_[longstring].panic) from the "System Diagnostic Reports" drop down
  3. File > Save a Copy As... > save file to folder of your choice

UPDATE:

Onyx is the most likely culprit, however, the option for clearing logs/reports is located in multiple places:

  • Cleaning > Logs > System Diagnostic Reports
  • Automation > Cleaning > Logs, including Diagnostic Reports

Uncheck these options if they are checked.

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