Mac Pro RAID array

Discussion in 'Mac Pro' started by MacProPonent, Jul 28, 2009.

  1. MacProPonent macrumors newbie

    Jul 27, 2009
    I purchased an early 2008 MacPro some time ago with the Apple RAID card and a single 15K 300 GB SAS drive. Later, I purchased two additional 300GB SAS drives with the intention to upgrade the system disk to a 600 GB RAID 5 array consisting of the three drives. My problem is that I can not add the system drive to the array, so I figured that I have to clone it and boot from the clone first. In the 4th bay I have a 300GB SATA drive which I'm attempting to use as the new one and have tried cloning it with ditto and rsync as outlined in

    However, I am unable to change the boot partition in the system preferences after making the clone. What are my options? Some sources suggest that using a RAID array as the system partition is not a good idea. Why would this be? Has anyone else even tried this?
  2. Tesselator macrumors 601


    Jan 9, 2008
    I dunno about Apple's RAID card but I boot from a RAID0. It's a massive difference in speed. The whole system feels much faster - everything. This is why some people recommend it I suppose.

    As for the cloning I dunno why it's not working for you. I've done it with CaarbonCopyCloner and also SuperDuper and both worked. With CCC I had to run it twice tho. For some reason it just decided to skip about 50 Gigs of files. :(

    Maybe someone else will know.

    Did you try rebooting and holding down the Option key before the grey blanket?
  3. gugucom macrumors 68020


    May 21, 2009
    Munich, Germany
    I recently used the software RAID0 in OS X to set up a boot partition with two HDs. I installed the system from scratch and migrated from my MBP. Next I made a RAID0 from SSDs and cloned the system from one RAID0 to the other. It worked without a hitch.
  4. MacProPonent thread starter macrumors newbie

    Jul 27, 2009
    I cloned the system partition with CCC and tried rebooting with the option key as you suggested. It had no effect.

    Perhaps I should make a backup with Time Machine and reinstall from scratch?

    This is not quite as easy as I originally thought. Am I a victim of the slick Jobs propaganda machine?
  5. geoffreak macrumors 68020


    Feb 8, 2008
  6. zebity macrumors member

    Aug 1, 2008
    The Process...


    the process to create 3 disk RAID5 boot from single Disk is:

    1) Must have 4 disks in machine (1 bootable)

    2) Boot machine from DVD and then go into RAID Utility and set up 3 spares disks have single RAID5 volume.

    3) Wait for (2) to complete.... this can be a very slow process taking up to 24 hours, depending on your disk size. Do not put anything onto RAID5 Set until it has completely initialised.

    4) Reboot machine from your single Disk and run CCC telling it to copy the Boot Disk vertabatim to the RAID5 Volume.

    5) Once (4) is complete go into System Preferences and select the "Startup Disk" option and choose the RAID5 Volume as boot disk.

    6) Reboot....

    7) Once you are on new RAID5 Volume I recommend that you setup your prior Boot disk as a JDOD+ RAID volume as this will mean that it gets enhanced performance as a result of using RAID cache. I also recommend that you use the spare disk as "backup", as Mac Pro RAID card has very poor hot recovery capability in the event of a disk failure on one of your RAID5 disks. I have had the Rebuild fail on 2 occasions.


    (MacBook Pro, Mac Pro, Mini Mac)

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