Can I create a new partition without losing data?

You can do it, but I would not do it unless I had a backup of the data already on the drive. This is not because I think the process itself is risky, but because any number of "bad things" can happen as Disk Utility is moving data around the drive to make room for the new partition. What if there's a power outage during the procedure? Or there may be existing data or disk directory corruption, and the process of moving data to create the new partition may make the problem worse.

Now, if you do have a backup of the data, then you may want to take the more conservative approach and do a regular re-partition. That will wipe the drive, but you can then restore the data from the backup.

Also, is this the internal drive used to start up the Mac, or an external drive?

Steve Cooper wrote:
Everything I read, including Disk Utility Help, says that I can create a new partition to occupy the currently unused half of the disk, without losing any data that's currently on the disk.

DU can't do that !

there is a 3rd party app, though it's not free, that can. take a look @ iPartition.

however, whatever you do, you should be well backed up !

Message was edited by: Jolly Giant

Starting with Disk Utility for Leopard, it can do it.

Kenichi Watanabe wrote:
Starting with Disk Utility for Leopard, it can do it.

right, starting with DU. it basically means wiping the drive, though.

iPartition will put a 2nd partition on the drive without the need to do that.

No, starting with the Disk Utility for Leopard, you can add a partition withOUT wiping the data already on the drive, as long as the new partition is added after the existing partition(s) and there is sufficient free space to allow Disk Utility to move data around as needed to accommodate the new partition.

Kenichi Watanabe wrote:
No, starting with the Disk Utility for Leopard, you can add a partition withOUT wiping the data already on the drive, as long as the new partition is added after the existing partition(s) and there is sufficient free space to allow Disk Utility to move data around as needed to accommodate the new partition.

okay, did some research and stand corrected.

thanks !

So, the best solution is to backup data on other drive, the use DU for creating another partition, am I right?

OR

use third party software e.g iPartition, to create partition without the need to backup all data, like that?

iUnique wrote:
So, the best solution is to backup data on other drive, the use DU for creating another partition, am I right?

OR

use third party software e.g iPartition, to create partition without the need to backup all data, like that?

let's put it this way: you should always be well backed up (bootable clone of your startup disk and/or full time machine backup). this goes especially when making major changes to your startup disk.

in the case of the OP, since there is plenty of space on the startup disk, he can use DU to create another partition. if you have a fairly full drive, iPartion would allow you to do that without the need to completely wipe your drive and partition it then.

With Disk Utility, the two options are (1) add a partition taking the precaution to back up the existing data, or (2) if you have a backup of the data anyways, do a regular re-partition that wipes the drive and restore the data from the backup. (2) is the more conservative (less chance for error) option, especially if there is a lot of existing data on the drive. You can do (1) without a backup, but that would be risky.

Since I have not used that third-party utility, I cannot comment on that option.