07-28-2011, 10:17 AM

I would like to migrate over to Lion, but my Mac and a variety of software apps are vital to my business. So I'd like test the waters with Lion, but be able to revert back to Snow Leopard if necessary. I'd also like to restart from scratch with a fresh install vs migrating all my apps over. I think reinstalling what I use from scratch would be faster and cleaner than trying to sort through all the apps and crap I've accumulated over the last 5 years. (Haven't done a fresh install since Leopard came out. Migrated to SL, but that bought everything with it.)

I have a 500gb internal drive in my MBP. At the moment I have 249gb free. I suspect that about half of that is crap I don't use any more.

Hypothetically, can I do this? (although others will I'm sure suggest other ways to reach the same end goal)

I'd like to partition off 200gb and install Lion in the new partition so I can dual boot SL or Lion. I want to take my time methodically setting up Lion. If at any time, I run into a software deal breaker that forces me back to SL (ie Outlook 2011 turns out to be a buggy as some claim), I can just go back to the SL partition.

Here's the part I'm not sure about... After a few weeks, once I'm completely comfortable with the Lion, can I delete my original SL partition so that the newer Lion partition becomes the sole volume on the drive? At that point, I'd be looking to boot automatically to Lion just like I had reformatted and installed over top of SL.

07-28-2011, 10:32 AM

Originally Posted by Jaygray

Here's the part I'm not sure about... After a few weeks, once I'm completely comfortable with the Lion, can I delete my original SL partition so that the newer Lion partition becomes the sole volume on the drive? At that point, I'd be looking to boot automatically to Lion just like I had reformatted and installed over top of SL.

Once you are satisfied with Lion and are ready to ditch Snow Leopard entirely, use Disk Utility to delete the SL partition. Then use Carbon Copy Cloner to completely clone your Lion partition to the old SL partition. Once done, boot into the newly cloned partition. Once you are satisfied it works to your liking, you can delete the "old" Lion partition and resize the new one to take up the whole drive if you like.

You should, as always, have an external backup of all this just in case something goes awry.

07-28-2011, 10:45 AM

So it sounds like a partitioned HD has a master/primary partition and any number of secondary partitions. The master/primary cannot be removed, but you can empty the primary, clone the data from the secondary, then delete the secondary which has the same net effect?

07-28-2011, 10:59 AM

Originally Posted by Jaygray

So it sounds like a partitioned HD has a master/primary partition and any number of secondary partitions. The master/primary cannot be removed, but you can empty the primary, clone the data from the secondary, then delete the secondary which has the same net effect?

Well you can remove the first partition just fine and still use the 2nd. The problem is that you can't resize the 2nd partition to fill in the space above it… only below. That's the only reason I'm suggesting it that way.

07-28-2011, 11:56 AM

One other thought I just had…. clone the SL partition now to the second partition; boot from that and wipe the first partition, then install Lion to that. When Lion is working to your satisfaction, you can wipe the second partition and be done.

07-29-2011, 07:05 PM

Just a follow up on my progress with this. So far, my transition has been smooth.

I booted from a CD and ran Disk Utility. Tried to partition the drive and it failed. Ran "Repair Disk" and tried the partition again. Worked this time. Took a couple hours to compact the Snow Leopard partition. When it was done, I had SL running in a 300gb partition and a blank 200gb partition. Installed Lion to the new partition. I can now boot to either OS. I've basically got Lion set up the way I want it. When one OS is running, you can still view the other OS as a drive in Finder.

A couple notes on software compatibility...

Thus far Microsoft Office 2011 has worked fine. Despite all the negative reports, I've had no issues at all.

I've stuck with Acrobat 9 for quite a while now, as Acrobat X would not play well with an old 11x17 printer I have. I was a little concerned about this, but so far it turns out Acrobat 9 is Lion compatible.

I have sufficient free space on the drive, so I'll probably leave the SL partition in place for the time being. No reason to remove it until I need the space.