How can I move my whole OS from one hrd drive to another?

I have a (relatively) new MacPro. I ordered it stripped, with only 2GB of memory and the basic 320 GB hard rive. From aftermarket I upgraded the memory to 16 GB and put in two 1 TB drives. As delivered, the OS was on the 320TB drive and most of my software is there, too.

I would now like to my OS and installed software to a roomier drive (probably another 1 TB jobbie)

How can I do this painlessly?

One idea I had was to put the new drive into the still empty 4th drive bay and just copy one drive's content to the other. Then swap the drives physically.

Do I need to do anything to direct the machine to the new startup drive?

Will this work?

Put it on whatever drive you like then change the startup drive to the one you want by selecting it in System Preferences>Startup Disk.

You must make a bootable clone, and not just copy the current startup disk.

Something like SuperDuper is perfect for this. It's free for cloning and backup. Additional features scheduling, etc. are unlocked with purchase.

(edited to correct link URL)

When I got my PowerMac (2Gb RAM, 320Gb drive, just like the OP), I ordered a 1Tb Western Digital Caviar Black along with it and immediately loaded SuperDuper and cloned the original 320Gb drive to the 1Tb drive and made that my primary. The original drive is in safe storage, just in case the 1Tb drive goes south, along with it's backups.

.... make that drive bootable, as mentioned in post number 1, above?

If so, that sure sounds like the best/easiest way to go!

answer to your question, but if you're worried about it, there's probably a simple fix to ensure that the disk you're restoring to has the proper boot sector -- namely, after booting from the installation disk (holding down option during boot and selecting the CD when it appears will work, though there's another preferred command: maybe option-c?)and getting past the first screen, pick Disk Utilities from the menu bar, choose the disk you're restoring to, and use Disk Utilities to repartition it with 1 (not "current") partition, using the proper format for a bootable drive, which I think is "OS Extended (Journaled)." Afterwards, leave Disk Utility and proceed with the TM restore to that drive, again from the menu bar: it's reasonably straightforward and intuitive. But it can take a while. At the end, you will reboot (automatically, I think) into the restored drive: there is one frustrating aspect, which is that the TM restore takes a while, if you have a lot to restore, and it doesn't restore some stuff (like caches) that must be rebuilt, so the first reboot after the restore can take a surprisingly long time (I've waited an hour or more with my fingers crossed hoping the machine really finally boots -- but it always eventually does for me)

...... go through all those endless authorization dickerings with the Microsoft Morons?

on guesswork. I think (but am not certain) that the answer to your question is No, TM won't backup your Windows/bootcamp partition: this guess is based on (1) some quick googling and (2) the fact that OSX is incompatible with the NTFS file system -- I bought special software (Paragon NTFS) to be able to drag and drop files back and forth between my OSX installation and my Windows/bootcamp installation, so I could do things like download in one OS and retrieve in the other. Windows has its own backup mechanisms. If you have multiple internal drives, why not keep your primary OSX alone on one drive and your Windows installation on a separate drive, so there is no possibility of one screwing up the other?

System Preferences > System > Startup Disk

..... which is still open.

Presumably all my old drives will be recognized for what they are:

320 GB which is now the boot drive will be for ..... I dunno what. Maybe to back up another machine on our network.

1T Drive 2 will stay for the current purpose - my data files

1T Drive 3 will stay for the current purpose - Time Machine back-ups

(New) 1T Drive will be the new boot drive with all my apps and system files.

like I did, in the event that your new 1TB drive dies.

Hmmmm ...... good idea, indeed.

I also have a MacPro-how sweet it is ..
The comments here are mostly right on, a few suggestions:
"Carbon Copy Cloner" has worked perfectly for me and I prefer it on estectic grounds to superduper (I own both).. It also tries to make a sector copy first.
Clones come in 2 flavors-exact sector by sector copies which produce identical copies but require the same size volumes etc..but are quicker than-
File by file clones which copy the entire drive file by file (changing references on the way etc.) but can move to a different size partition.

It has worked out very well for me to move my home folder to a separate partition, see
This allows having a smaller os ,and/or different versions on each drive

I use a program called "WinClone" to do the cloning of the bootcamp partition and it works great .

There is also one program that will allow changing the partition size non destructivley-Drive Genius found it usefull when clonning around..