How do I do a clean install of Yosemite?

[SanFran95]

I read in another topic, that beta version of Yosemite does not upgrade the recovery partition.

Can somebody please confirm whether it does or doesn't? I would rather just upgrade and then do the fresh install via cmd+r.

It does upgrade the recovery partition. I have done a fresh install that way, and it worked for me. If you are still not sure, you can just start the recovery partition with cmd+r and see (the OS X logo has changed to Yosemite, although it's not easy to see the mountain in the X).

Also I found out that it's very easy to downgrade/reinstall Mavericks with OS X internet recovery. In my case I just went to the recovery partition with cmd+r, then erased the Macintosh HD partition and created a new one. Then instead of installing Yosemite I just turned off my Mac, which made it start up from Internet recovery.
Disclaimer: By doing the Internet recovery part, it depends on which Mac you got (if it didn't come with Mavericks, you might not have an Internet recovery partition (which means you end up with no operative system), or your Mac may install Mountain Lion instead).

 

[forza69]

I just downloaded the Public Beta but how do I do a clean install of the OS? i've never had to reinstall OS X or anything before.

Even though Yosemite PB 2 is pretty stable, I wouldn't have it as my main OS. I recommend partitioning your primary. Ill be doing a clean install of Yosemite only when the final version is released. I suggest you do the same.

 

[537635]

Thanks!

 

[576316]

I would definitely install it on a separate partition.

So I should install it on a separate partition and then purge the original install partition when I'm done?

 

[Apple_Robert]

So I should install it on a separate partition and then purge the original install partition when I'm done?

I was referring to the beta. I don't think that is necessary with the official release. You can upgrade over your current OS later today or do a clean install on your main partition.

 

[crazyman3005]

I was referring to the beta. I don't think that is necessary with the official release. You can upgrade over your current OS later today or do a clean install on your main partition.

How would you do a clean install on the main partition?

 

[StorrowDrive]

How would you do a clean install on the main partition?

http://support.apple.com/kb/ht5911

 

[fenderbass146]

I do it a stupid long but effective way. I upgrade to yosemite like normal, then once I have the yosemite recovery partition I wipe the hdd and restore via that.

 

[Apple_Robert]

I do it a stupid long but effective way. I upgrade to yosemite like normal, then once I have the yosemite recovery partition I wipe the hdd and restore via that.

What you did is not the same recovery partition set up, that will be available to those who install the GM today.

 

[fenderbass146]

What you did is not the same recovery partition set up, that will be available to those who install the GM today.

I haven't done it yet, that's what I am planning on doing once they release the Official Yosemite. I am on GM 3 right now.

 

[576316]

I was referring to the beta. I don't think that is necessary with the official release. You can upgrade over your current OS later today or do a clean install on your main partition.

I wasn't sure you'd get back to me cause the thread was old.

I'm gonna create an installer on one of my portable hard drives (so it's big enough) and then write over my SSD. I've made certain I have a Time Machine back up but I've also saved all the important files and folders externally so I can place those back without restoring from TM and making the clean install pointless.

 

[sarahaa]

I get this error about a second after entering my password. I have used a lacie (8GB) and sandisk (32GB) thumbdrive formated, MACosEJ

open terminal and copy and pasted the string and then nothing.

Password:
Erasing Disk: 0%... 10%...
Error erasing disk error number (-69888, 0)
A error occurred erasing the disk.
iMac:~ user$



can someone please advise?

Just a further bit of info for anyone having this frustrating problem. It was happening to me, over and over.

It turned out that the line I had copy/pasted had a space between Volumes/ and the drive name.
i.e. "volume /Volumes/ FlashInstall". Removing that space after Volumes/ fixed the problem. So it should read:
"volume /Volumes/FlashInstall"

The syntax has to be exact or you get the error. If in doubt, check your command line against a couple of different sources and experiment with that destination syntax.