View Full Version : Clean Install from Snow Lepard ??

7th July 2010, 02:41 PM
Hi all
I am wanting sell my macpro and obviously want to erase my HD and reinstall the os. Problem is I don't have the original discs only the snow leopard upgrade.
I don't seem to be able to do it from this. Is that true?
Is the any way i can wipe and do a erase and clean install from the snow leopard discs only??
Any help appreciated.

7th July 2010, 02:56 PM
You should be able to boot from that CD holding down the "C" on the keyboard and then run disk utility to wipe the disk, once that is finished you can than continue running the install.

7th July 2010, 05:45 PM
Insert that disk into the drive.

restart your machine and hold down the option key at the same time. When the computer restarts you will get two icons on the desktop, your hardrive and the MacOSX DVD.

Click on the dvd icon to boot from it. When it boots you will get the language option. English is the default. Select your language and hit “Enter”.

After another minute you should see a screen appear that says Welcome to OS X Snow Leopard. Go to the Utilities menu and select Disk Utility. You should see your hard drive over on the left-hand side of the window. Click on it once to select it. Now, click on the “Erase” tab. Make sure the Format drop-down box is set to “Mac OS Extended (journaled)”. Click on the “Name” text box and name your new hard drive. Click on the third button on the bottom right that says “Erase”. Snow Leopard will ask you if you are sure. You did back everything up right??? If so, go ahead.

I think there are 3 erase options. Zero Out Data, 7-Pass Erase and 35-Pass Erase.

Descriptions are provided below each option. A 7-Pass Erase should be sufficient, but performing a 35-Pass Erase is even more secure. The more secure option you choose the longer it will take to perform the erase. Select the OK button once you’ve chosen an erase option. You will be returned to the Disk Utility main window.

Click on the Erase Button

You will then be asked if you want to continue.

Once the erase is done, then go back to your Install process and hit continue and the DVD will then do a clean install of the OS on the clean drive.

EDIT: Actually - the new Podcast "Ask MacTalk (http://www.mactalk.com.au/2010/07/07/ask-mactalk-episode-1/)" discusses Clean Install

7th July 2010, 06:06 PM
7 pass and 35 pass erase are so more secure than the standard 1 pass zeroing out of all data. They also take 7 times and 35 times as long, which gets ridiculous on large disks.

If you didn't have any confidentital data on the disk, you also have the option not to overwrite the drive at all, merely reformat. This is almost instant.

7th July 2010, 07:08 PM
What do you guys think you're going to achieve by zeroing out the data even once let alone 7 times?

If you're worried about your donkey porn, I mean data, getting into the wrong hands then (a) zeroing it once should suffice because it really is gone after that and ASIO actually can't recover stuff like they do on TV; or (b) that even after 35 times, Abby Scuito (http://www.imdb.com/character/ch0020059/bio) will still be able to recover enough of it to put you in prison for the murder of a marine anyway, so why bother?

All seriousness aside, there may be some circumstance under which zeroing blocks is a valid thing to do, but doing a clean erase so you can reinstall on your own computer is not one of them unless you've had trouble with your disk. Even then it will only fix a small number of disk issues.

Ooops: Just realised the OP is wanting to sell the machine - sorry guys! Still think once is enough though. :o