can I partition an ext hd thats already formatted/partitioned?

Discussion in 'macOS' started by Wie Gehts, Sep 3, 2009.

  1. Wie Gehts macrumors 6502

    Joined:
    Mar 22, 2007
    #1
    I need to put into service one of my big ext hd's to use as a place to clone my system hd to. Superduper guy tells me it should have its own partition all to itself.

    So if I have a drive thats already been formatted into a single partition with a lot of files on it, can I use disk utility to create another partition using the free space in order to be able to clone onto without messing up the files already on that drive?

    thanks
     
  2. gr8tfly macrumors 603

    gr8tfly

    Joined:
    Oct 29, 2006
    Location:
    ~119W 34N
    #2
    Provided the drive has been partitioned using GUID, then you should be able to add a bootable partition. GUID partition map is required to boot Intel Macs. You should be able to resize and create a new partition without affecting the existing data. It depends on how full the drive is and whether there are files in the physical space that's being freed up.

    In Disk Utility, select the drive from the list on the left. From the Partition tab, you can click the "+" button to add another partition. Slide the separator bar to change the size of the new/old partition.* Optionally, slide the single partition's enclosing frame smaller to create free space, *apply the change, then select the new free space to add a new partition.

    *Disk Utility will inform you if and which partitions will be erased and which will be left unchanged. Read the information carefully before you commit to any partition changes.

    btw: You can use Disk Utility to clone your drive. It's the only tool I use. Just boot off your OS-X install disk and run Disk Utility from there. Then, use Disk Utility's Restore tab to make the clone. Make sure to set it to "block copy" by checking the "erase destination" box. (Oh, and it goes without saying to verify the proper source and destination volumes.)
     
  3. Wie Gehts thread starter macrumors 6502

    Joined:
    Mar 22, 2007
    #3
    ok thanks.... yeah, its a 1tb drive that probably has 2-300 gb already on it so there lots of room. i also always format GUID.

    and if worse come to worse, this drive is only holding backup data so if i lost it it can be replaced. it'd just take a bunch of hours to do so.


    thats got me thinking....the files on there would all have to be in one condensed 'area', no? cause if the files were all over the drive, you couldn't get a clean section to partition without it telling you your gonna trash something i guess.
     
  4. gr8tfly macrumors 603

    gr8tfly

    Joined:
    Oct 29, 2006
    Location:
    ~119W 34N
    #4
    Sounds good. You probably still have free space, so you just need to "+" a new partition.

    If there are files residing in the space needed to adjust or create a new partition, Disk Utility will give you an error. However, if it's already free space, it's not going to look for files there. If you do end up with files "in the way", you can either copy the contents to another drive and back again, or use something like iDefrag to consolidate the files.
     
  5. Wie Gehts thread starter macrumors 6502

    Joined:
    Mar 22, 2007

Share This Page