Size of Leopard OS versus Tiger?

Question

I'm about to install Leopard (when 10.5.3 is released) and I want to do a weekly, bootable back-up of my system to an external firewire drive, using CCC. The current size of my OS X Tiger (10.4.11) contents is about 75 Gigs.
Question: How many Gigs would be added to this system's size by virtue of running Leopard versus Tiger?
I ask because I'm trying to figure out what size the external hard drive needs to be.
There will be two other volumes on this back-up drive totalling about 200 Gigs. A 500 Gig might be fine but a 750 Gig might be a much better value -- particularly with the flexible partitioning capabilities in Leopard.
Suggestions?

Answer 1

Hello,
I'm trying to think about what would be my backup/DRP strategy in the situation you describe.
- Why the bootable copy of Tiger? You don't want to go back to Tiger. It'll useless (given the benefits of Leopard of Tiger). Many, many changes have occurred with Leopard. Nearly all of them are "under the hood". This makes that your idea of a bootable clone of Tiger doesn't yield to any benefit, beside archiving files that you may want to keep handy, like fonts (not all fonts!).
In that case. I would recommend you get a cheap pocket-sized FW400 drive that you'll keep in a safe place for a couple of years, then erase and reclaimed. The Unix command-line utility "asr" is good enough to get you this cloning job done.
- It seems to me you have some critical material for your other larger partition: Your Logic Audio session files.
I would personally investigate in a RAID based drive, where hardware redundancy will get you the level of security against (hardware related) data loss risk.
- You want to create a third partition for an incremental backup ? Assume 2 to 3 times the size of your data to backup when considering the size of your incremental backup solution. Time Machine is very good at keeping numbers down but a month worth of daily changes will get you very close to these figures.
So, you're bound for 3 separate hardware.
- The Bootable system drive clone is bound for recycling in a short timeframe. Once you'll have done that, you'll figure out you've wasted the space of this partition on that drive. You can always plan to delete that partition and extend your Sound files partition ... but if something goes wrong, you'll end up loosing a lot.
- The Volume where you want to store your Snd files is very critical - specially if this is a bread-making work. Don't hesitate for a hardware RAID.
- You don't want to put all your eggs in the same basket (backup volume on the same physical media as live data). An incremental backup requires numerous dedicated (cheap) hardware. After you've reached the capacity of your Volume, what are you going to do? Delete it all and start a new incremental backup again? I bet you're going to keep that first back for a while and get a new drive to start a new incremental backup. Perhaps, you're going to recycle the first backup when the second one will reach max capacity, thus rotating your drives as destination of your backups.
You have 3 different needs. To rely on one single and common hardware to satisfy them is - IMHO - not an efficient strategy.
I hope this will help you.
Thierry