How Can Multiple Hard Drives Act As One

Discussion in 'Mac Basics and Help' started by c.greene914, Jul 25, 2007.

  1. c.greene914 macrumors regular

    c.greene914

    Joined:
    Jun 3, 2007
    #1
    Here is my dilemma, I want to use a Mac Mini for a dedicated media server. However right now I have two 750gb hard drives, both reasonably full, meaning soon I will have to buy a third external HDD. The Mini has 4 USB ports on the back. Is there a way to plug multiple external HDDs into multiple USB ports and have them act as one huge HDD?

    The reason I need this is because I plan to keep everything in iTunes and just leave it open/running. In order to do this I have to have one iTunes library and locate it in one place, not four different library folders spread out over four different HDDs.

    Can someone help me with this, or recommend a better way to do it?
     
  2. Queso macrumors G4

    Joined:
    Mar 4, 2006
    #2
    You can do it in Disk Utility by setting up a RAID array, but to be honest you'd be better off buying an external RAID enclosure and mounting drives in there. Try and use RAID5 if possible. If your volume spans multiple disks on a normal RAID0 array and one of them fails you lose the entire volume. On RAID5 you can lose a disk and your data remains intact, which means you can rebuild the array simply by replacing the faulty drive.

    The downside of RAID5 is that you need a minimum of three disks and one of them is effectively wasted spacewise. So three 750GB disks would give you 1.5TB, not 2.25TB. You would also need to back your data up off the disks before creating the array.
     
  3. c.greene914 thread starter macrumors regular

    c.greene914

    Joined:
    Jun 3, 2007
    #3
    I back everything up on disc so I'm not to concerned with HDD failure. The reason I don't want to mount everything in one RAID array is both of my HDDs are still under the Seagate 5-year warranty and putting them in another case will void that. The 5-year warranty is one of the reasons I bought a Seagate so I would like to keep that. If I can keep them in separate cases and just configure them to RAID 0 in disk utility, that would be my best option I believe.
     
  4. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #4
    I'm pretty sure there's nothing that stops you from doing this. Someone blogged about taking four iPod Shuffles (when they first came out), putting them on a USB hub, and making a RAID out of them. So the fact that they're in different cases or on different controllers doesn't seem to matter to Disk Utility in terms of making a software RAID.
     
  5. balamw Moderator

    balamw

    Staff Member

    Joined:
    Aug 16, 2005
    Location:
    New England
    #5
    Note too that unix based OSes don't really follow the same concepts as Windows w.r.t. "drive letters". Yes, they auto mount at separate mount points in /Volumes, but you can easily make a symbolic link to a file or folder on a volume2 that will be largely indistinguishable from a file on volume1. Plus you can even make the mount point for volume2 be somewhere on volume1.

    Relevant links:

    http://www.macosxhints.com/article.php?story=2001110610290643

    http://www.macosxhints.com/article.php?story=20050805062520199&query=mount+point

    B
     
  6. c.greene914 thread starter macrumors regular

    c.greene914

    Joined:
    Jun 3, 2007

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