View source for Osx

== Shortcuts ==

* Hold down "d" on boot to do a hardware test
* Hold down alt/option on boot to boot into safe mode
* Hold down apple + "s" on boot for single user mode
* Hold down apple + "v" on boot for verbose mode
* Command + Control + Power also brings one into single user mode

== dynamic_paging ==

I noticed on my MacBook Air that after a few weeks I would run out of diskspace, without downloading anything, forcing me to reboot. Before I did, I checked /tmp and nothing looked large enough. Bryan F from [yh] pointed out "man dynamic_pager"

 $ ls -la /private/var/vm/swapfile
 $ sysctl vm.swapusage

I noticed gigs worth of files! At your own risk: 

 $ sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.dynamic_pager.plist

and reboot. After reboot, sysctl vm.swapusage shows 0 and /private/var/vm/swapfile is empty. replace "unload" with "load" above to revert to default.

== Make application default ==

When trying to open video files, I noticed that it defaults to Quicktime, and I wanted it to default to VLC. With no obvious way to delete quicktime, I wasn't sure what to do. While I tried to setup "Always open with" and pick VLC, that didn't seem to work. In the end, I discovered you need to right click on the file then

 Get Info -> Open With (Choose VLC) and then click "Change all..."

== Re-install ==

Do this at your own risk, and after backups. These steps worked on a MacBook Air with OSX Lion 10.8!
* Install [http://blog.gete.net/lion-diskmaker-us/ Diskmaker 2]
* Using the App Store, download the InstallESD.dmg
* Follow the steps in Diskmaker 2 and install the image on an 8G USB stick
* Reboot holding down the ALT key, choose the USB stick as the boot device
* Choose Disk Utility, and Erase the main partition/image
* Close Disk Utility and Install OSX

== Format a disk on the command line == 

In Terminal (Applications -> Utilities) on the command line type:

 diskutil list

will show you all of the disks. In my case, disk1 is the one I want to erase and format:

 diskutil eraseDisk HFS+ UntitledUFS disk1