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sammich

macrumors 601
Sep 26, 2006
4,305
268
Sarcasmville.
You'd be going from a blazing fast internal SSD to an external USB drive which is only a temporary solution. So:

was wondering what the performance was like afterwards?

Horrible in comparison. Trust me, everyone will agree.
 

name99

macrumors 68020
Jun 21, 2004
2,410
2,322
has anyone installed osx onto a external usb harddrive using a macbook air?

was wondering what the performance was like afterwards?

would help to get around internal small hd space....be good when using at home and also using external monitor....

:for those that dont know....

http://www.maciverse.com/installing-snow-leopard-onto-an-external-hard-drive.html

What exactly are you asking? Can you run OSX from an external USB drive? Sure, it's trivial.
Does it work well? Depends on what you are doing and the drive. The most obvious limitation of a USB drive is the bandwidth, so that copies of large files (eg movies) will run about half to a third as fast as on an internal drive.

On the other hand, if the external drive is an SSD (eg OCZ Enyo or equivalent) you will get wicked fast random access, and the result will seem faster than a normal magnetic drive. Enyo is also small enough and light enough that you can probably tape it behind the top screen of the MacBook Air if you want, and still have pretty good portability. Even if you get a standard fast external drive (the latest Seagates are pretty good and slightly smaller than their Western Digital equivalents) it will probably feel faster than the very slow magnetic drive in the old MacBook Airs.

As for how to do it, the simplest method is plug the drive into the MacBook Air, format it properly (because when you buy it, it is probably NTFS formatted). Formatting properly means BOTH
- using GUID partitioning AND
- creating a JHFS+ partition.

With that done, download Carbon Copy Cloner and run it, cloning your internal drive to the external, then use Startup Disk in System Preferences to tell the system to boot from the external drive.
At some later point, if you wish, you can set up sym links from the external drive to the internal for the large media folders (Music and Movies).

Personally what I would do is get an Enyo, and use sym links to store Music and Movies on the internal drive, and have everything else on the external. This is the config I have for my 2007 iMac --- external USB SSD, with media files on the internal iMac drive.
 
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