I'm excited about Time Machine, but for me there a lot of questions:
Has anybody seen any recommendations for the size of the TM hard drive? Can I easily move the TM data to a bigger hard drive? What happens if you use a laptop without the TM hard drive? Will the TM information temporarily stored on the laptop and then updated on the external hard drive once you reconnect it or do you lose it?
Steffen
Yes to all of your questions.
Time Machine works by querying something called FSevents, which is basically a log of all changes made to the file system. So imagine the following:
You connect your external drive to the MacBook, it makes a full backup.
You use the MacBook on its own for 2 to 3 days. All changes made are logged to FSevents.
When you reconnect the external drive, Time Machine refers to FSevents and can quickly see what has changed since the last backup, and then it backs up those files accordingly.
What you dont get is the hourly/daily backups while you are not connected to the harddrive... it will just back up all changes. If the external drive is constantly connected, this is what happens.
Full backup
Every hour, TM refers to FSevents and backs up any changes within that hour.
It does this for the most recent 24 hours.
Stuff older than that is kept daily for 30 days.
Then monthly I believe, until you have no space left on the drive.
Its actually a very clever implementation of backup.