Partitioning external HD before Leopard upgrade?

I have a Lacie 500GB drive arriving today, and Leopard is sitting on my desk waiting to be installed this weekend as well (I currently have Tiger 10.4.10 on my MBP). I'm planning to do an Erase-and-Install to make sure the new OS works well, so prior to that I want to be able to move several things (e.g., my iTunes Library) permanently onto the Lacie. I don't want or need Windows machines to access this drive ... it's intended solely for use with the MBP.

Here's the source of my concern: I also want to partition this drive in two chunks and use one part of it (maybe 200GB?) for Time Machine after Leopard is installed, while continuing to use the remainder for things like my iTunes library, multimedia projects, etc, which I need to move to that drive BEFORE Leopard has been installed. I'd like to know how (or if) I can set up the partitions while I'm still running Tiger to allow me to easily switch the one partition over to Time Machine's use after Leopard is installed, without having to affect the iTunes Library and other data that will already be on the Lacie's other partition by that point.

Any thoughts? Am I worrying about this too much? (I've never formatted a disk for the Mac world before, having been a long time PC guy, so I'm not sure what to expect.)

I'd let Leopard partition it. Just put your files on it, then install Leopard. Leopard's Disk Utility is much better for partitioning, IMO.
Yes, it will allow you to make a new partition with existing data on the drive in Leopard.
That's just my thought though.

I would do it while you have Tiger installed. Just make the 2 partitions in HFS+ format, and it'll work fine with Time Machine.

I haven't tried partitioning in Leopard while keeping the existing data on the drive, and I'm sure 99% of the time it works fine, but you never know when something will happen and your that 1% that loses all your data.

AlyciaAnimation said:

I would do it while you have Tiger installed. Just make the 2 partitions in HFS+ format, and it'll work fine with Time Machine.

I haven't tried partitioning in Leopard while keeping the existing data on the drive, and I'm sure 99% of the time it works fine, but you never know when something will happen and your that 1% that loses all your data.

Click to expand...

I would tend to agree about avoiding even that low risk factor, but here's one source of my concern. In the following YouTube video, Chris Pirillo sets up a drive dedicated to a single Time Machine partition, in Leopard:

http://youtube.com/watch?v=m1QyFaIIrzU

It seems to me from watching this video that, during using Disk Utility to partition the drive, there were Time Machine specific options that he was choosing. Obviously those options wouldn't be available to me when partitioning under Tiger, and I'm wondering if I'd have to repartition in Leopard again anyway in order to get Time Machine to work at its best?

Done, no problems

I've finished this, and it ended up not being a problem at all. While still running Tiger, I configured two partitions on the external drive, both as Mac OS Extended (Journaled) and with the GUID Partition Table option selected, and then stored a bunch of data on one of the partitions before wiping the internal disk and installing Leopard. When I first hooked up the external drive again under Leopard, it immediately asked me if I wanted to use one of the partitions for Time Machine. I told it which one to use, and that was that! No need for any repartitioning under Leopard ... no need for much thought of any kind, in fact! Very nice.