How can I convert a NTFS drive to HFS+ without having to move the data?
It is an external drive of 2TB and I don't want to spend too much time moving the data.
This is required in order to be able to share the drive on Lion (smbx)
Sorry but there is no way to reformat a Hard Drive while keeping the current data intact. You can either move the data off, reformat to HFS+ then move the data back on or add a second partition that is HFS+, move the data to that partition then remove the old NTFS partition and expand the HFS+ one.
The OP has probably already solved this problem since posting 2 weeks ago, but for the record, smith is right, you will have to move the data one way or another to reformat to HFS+. And it must be journaled if you want a bootable partition. Lion doesn't support FAT32 or NTFS.
If you don't have room to make a second partition on the current drive to hold all the data, you will have to borrow, rent or buy another HD, and then set it to copy everything overnight or while you're at work.
If you're in a position to buy, look for a great deal, or a nice upgrade to what you have (nothing in between). Costco was recently selling a 3 TB MyBook (USB2) for $100, though USB2 will be much slower and have less longevity, especially given Apple's new Thunderbolt standard. Or, a high capacity can be had for about 7-10c per GB (~$150-200 for a 2TB) with FW800/USB3. Personally, I'd go for the upgrade, unless I were broke.
Once you transfer, you can sell the new drive (or if you have wiggly ethics, return it), or keep the upgraded drive and sell your old one after wiping it clean (triple pass erase and reformat).
You might also look at what you REALLY need out of all those backups. How important are those files, and how often do you use them? Unless you're doing DV / animation work, photography or you have huge media libraries (that you actually use!) you probably have a lot of wasted space.
It's easy to keep buying hard drives and filling them up. It's harder to sift through them for the real jewels ... or bite the bullet and dump all your old ideas to make room for the new.
Now there's an idea for a great backup solution: Only back up stuff that matters!