Can anyone offer a relatively simple explanation of how a double panic differs from other types of kernel panic on a Mac?
Simple as in … I'm not a developer, but I wish to understand these things a little better.
A loose description of panics of this type:
the phrase "double panic" on screen at the time of the panic
if there is a .panic file, it'll not include that phrase
sometimes there's no .panic file, which might explain why I can find only limited discussion of double panics.
An OS X 10.8.5 example
Screenshots below will also relate to a topic in the ZEVO area – I'll continue the support discussion there in due course.
Safari in front:
In the background, installation of Ubuntu 12.10 to a VirtualBoxVM:
In the background, Activity Monitor:
Running in the Dock: Finder, Activity Monitor, AntiRSI …
… Mail, Safari, Terminal, VirtualBox and VirtualBoxVM:
Nine swap files:
VirtualBoxVM writing to a virtual disk:
(Side note: with my very old but lovely iPhone, I couldn't get better photographs.)
What causes a kernel trap 0x00000008 (SCO Unix) (2005?) mentions:
… the Double Panic- the kernel panics while panicing.
It can be caused by corrupt driver code, but is more likely to be bad ram (or bad CPU, motherboard- anything that causes a bad instruction to get to the cpu)
– but the heading there is:
This is an ancient post with little relevance to modern systems.
I could find no up-to-date authoritative generic explanation.
In irc://chat.freenode.net/#macdev on 2013-09-25 in response to an earlier edition of this question, someone stated that it's clearly:
- a panic during a panic.