Updating OS X tends to involve downloading an installer from Apple’s site and then running it. What may not be clear/obvious is that the installer is deleted once the installation is done. In most cases this is probably fine… but if one should need it later, for whatever reason, it means repeating the process. At 5+ GB, this can be an unnecessary drain on resources. If one should find oneself in that boat, therefore, it may be prudent to back up the installer somewhere before doing the installation. I myself tend to make copies of all my installers on a Passport drive so I don’t have to hunt for them again.
Incidentally, having needed the Mavericks installer yesterday (and having thus discovered the above unsavoury phenomenon), I also found that searches on the Apple site for it were mostly in vain, despite the numerous posts on the ‘net ostensibly pointing to it (it appears Apple likes to have users find only the most recent installer). The solution, as it happens, was to open the App Store and go to ‘purchases’–where it was available for download.
In my case, it was a question of wanting to create a bootable USB so I could wipe my system and re-instal OS X (my system has been running slowly and I’m thinking a clean installation might resolve some issues–a ‘last ditch’ sort of effort I wouldn’t recommend unless it is necessary). Instructions to do that can be found here (among other places). In the event the link should somehow evaporate, the salient points are repeated here:
- Open a Terminal window
/Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia(the slashes make the blanks part of the file name, rather than command separators; here and below, all commands are to be entered on a single, despite possible appearances when viewing this or the original page)
- Format the USB stick using the Disk Utility in the Utilities subfolder of the Applications folder (use the Finder to get there if you haven’t got an immediate access stack on your task bar). Use a Mac journaled option.
sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app --nointeraction(you can probably name the USB partition anything you like in the previous step; it doesn’t matter much, it will be renamed here). You will need your administrator password, of course.
If you should wish to use this, reboot, and hold command-R immediately upon reboot; you will be able to choose your boot option.