Changing backup drives with Time Machine

Why not just get rid of some of the older backups?

 

I did this recently, I think with some help from some posts here.

Make sure both drives are connected & then launch Disk Utility. Click on one of the drive names in the left column (the main drive icon, not a sub-icon) & click the Restore tab across the top (far right). Then drag the icon of the older/smaller drive to the Source field & the icon of the new drive to the Destination field & click Restore. I found it worked best with Erase Destination checked, which is not a problem with a brand-new drive. When this is done copying & verifying (at least 2-3 hours!), the new drive will have the same name as the old drive.

Then rename the old drive & then open the Time Machine preferences & make sure it knows to use the new drive.

 

A larger drive will allow Time Machine to store backups stretching farther back into time. Perhaps moving to a 500GB drive will give you four months of backups instead of two.

However, the notion of "run out of room" on a Time Machine volume is sort of misguided. Time Machine is going to fill up whatever volume you give it no matter how large the drive is. That's just how Time Machine works. You could have an one point twenty-one jiggabyte backup volume and you'd still "run out of room" on it.

Do you want to have an archive stretching back farther in time than your current Time Machine backups allow? If so, then you should look into a larger drive. If not, then it sounds like 200GB is perfectly adequate for your needs.