Way to migrate Time Machine data to a new disk

I recently had to migrate all my TM backups to a larger drive.

You can successfully complete the operation using to the following tutorials:

• How To Move OS X Time Machine Backups To A New Disk
• A Bigger Time Machine without Changing History

SuperDuper! will do the job. You can use it for free to do what you want, and pay only if you want to continue to use it to do efficient incremental backups using its "Smart Update" feature.

For 10.6, Apple has included the following in Mac 101: Time Machine:

Mac OS X v10.6: How to transfer your back ups from your current hard drive to a new hard drive

If you upgrade to a new hard drive with a larger capacity, you may want to transfer your existing Time Machine backups to it before using it for regular backups. To keep your existing backups on your new, larger backup hard drive, follow these steps:

1. Connect your new hard drive.
2. In Disk Utility, make sure it has a GUID partition and is formatted as Mac OS Extended (Journaled). If needed, reformat the drive as Mac OS Extended with a GUID partition. If you do not know how, see the steps in this article. Note: Back up any data on the hard drive before you format it.
3. Select the new drive's icon on the desktop and choose Get Info from the File menu.
4. Make sure "Ignore ownership on this volume" is not enabled.
5. Open Time Machine preferences in System Preferences.
6. Slide the Time Machine switch to Off.
7. In Finder, double-click the current backup hard drive to open its Finder window.
8. Drag the folder "Backups.backupd" to the new hard drive.
9. Enter an administrator user name and password, then click OK to start the copying process. This may take some time to complete because all your backups will be copied.
10. In Time Machine System Preferences click "Select Disk…"
11. Select your new hard drive, then click "Use for Backup."

Now, on your new hard drive, you will have all of your existing backups from the previous backup hard drive plus have more room for more new backups.

(There are also instructions for Time Capsule and Mac OS X v10.6: How to transfer your back up from an existing Time Capsule to a new one.)

As a side note: when you are using a sparse bundle (like for remote backups) and if you made backups of really large files, then deleting those files from the backup (either manually or when Time Machine removes expired daily and hourly backups) will not automatically reclaim the disk space -- until Time Machine really needs it.

You can reclaim the space manually, and it may free a lot of space (possibly making migrating to a larger disk unnecessary, or at least giving your new disk all the possible space). See What is Time Machine doing? on Server Fault.