Osx

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Revision as of 19:29, 19 October 2014 by Franks (talk | contribs)
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osxbackups


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!