Recovering Data from Partitioned Drive

My external drive had my time machine backups, as well as other files in one partition. In the interest of organization, I tried to partition the drive. After reading up to make sure it won't be formatted in the process I did this with out backing up the drive.

Using Disk Utility I selected the drive, clicked "add a partition" (the little plus sign on the bottom) made sure the existing data side had plenty of space. The side with existing data said "this volume will not be erased" and when I hit apply it promised that a partition would be added and the other resized.

When it was done (took less that a minute even though there was about 200G) all the data appears to be gone (volume not erased my *****).

HELP!!!!! Can I get this back?

Never do anything to a hard drive unless you first make a backup. Partitioning doesn't destroy data, however, it removes or changes the "pointers" to where the partitions are located on the drive making it look like the data was erased.

You need data recovery software to see if you can get it all back. Or software to undo the partitioning. I just did a search to see if I could find something to undo the partitioning you did. I can't find anything for a Mac only Windows.

The next best bet is to use data recovery software. The best in my opinion is Data Rescue 3 from Prosoft. Here is the LINK. Note, however, this is expensive at $99 so I would advise you to download a trial version first to see if it can find all your data and recover it. You will need another spare hard drive to copy the data to as you can't undelete from the same drive.