Snow Leopard and Power Outage

[multicore]

OK, I'm coming from years with Panther, and then just a few weeks of Leopard use before I went to Snow Leopard, so maybe I missed the memo. But I have had my second power outage this month just today, and both times when I re-started my Mini it booted with the exact desktop it had when the power failed, with all the same apps open in the dock, and even the same tabs open in Safari. Very convenient, but I can't find any reference to the how of it. Anyone?

 

[misterredman]

Was the mac mini sleeping when the power outage occurred or were you using it? If it was sleeping maybe safe sleep is activated and the content of the ram is also saved to the hard drive.

You can check that with the following command, in the terminal:

pmset -g | grep hibernatemode

Here are the possible results:
# 0 - Old style sleep mode, with RAM powered on while sleeping, safe sleep disabled, and super-fast wake.
# 1 - Hibernation mode, with RAM contents written to disk, system totally shut down while “sleeping,” and slower wake up, due to reading the contents of RAM off the hard drive.
# 3 - The default mode on machines introduced since about fall 2005. RAM is powered on while sleeping, but RAM contents are also written to disk before sleeping. In the event of total power loss, the system enters hibernation mode automatically.
# 5 - This is the same as mode 1, but it’s for those using secure virtual memory (in System Preferences -> Security).
# 7 - This is the same as mode 3, but it’s for those using secure virtual memory.

 

[multicore]

Yes, it was sleeping both times. The terminal command returned #3. Thanks for the explanation misterredman.