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 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
dd an .iso
Instead of using Disk utility, I find it easier to simply dd your iso to a USB stick. Find out what your USB stick device is.
diskutil list
then I added the USB stick and ran the same command. Under the IDENTIFIER column it will show you the name, in my case disk1. Make sure it's unmounted:
diskutil umount /dev/disk1
then
sudo dd if="mydiskimage.iso" of=/dev/disk1
and then patiently wait. When it's done, if the numbers match for input and output, you should be good to go!
