11 Replies Latest reply: Dec 25, 2014 5:34 PM by dmltv
jadederea Level 1 Level 1 (0 points)

I have 4 Discs.

Mirrored raid sets

One Raid Slice is 'System Mirror'

One Raid Slice is 'Data Mirror'


There is a lock symbol on all 4 discs.  Status is online.


I can't delete the raid sets.  I can't unmount them.  I am the admin but the Disk Utility says  "Deleting RAID set failed.  Deleting RAID set failed with the error:  Invalid Request"

Mac Pro, Mac OS X (10.6)
  • Esther Mofet Level 1 Level 1 (130 points)

    You can't delete the RAID volume because the system is using it. If you're really intent on deleting it, then you could boot the system with an installation disk, then go to the tools menu and launch the RAID utility from there.

  • nielkmot Level 1 Level 1 (0 points)

    booted from a tiger installer dvd, i STILL see the mirrored volume as "online", and the disks all have padlocks next to them.


    any other ideas?

  • Peter Borbonus Level 1 Level 1 (100 points)

    Did you try to delete the raid with the RAID-utility (located in Utilities)?



  • Esther Mofet Level 1 Level 1 (130 points)

    Disk Utility won't let you do anything with a RAID volume. You'll need to use the RAID Utility. It's in the same menu when you boot from the installation DVD.

  • Julian Boolean Level 1 Level 1 (0 points)

    I have the same problem of not being able to delete my raid set.  The Raid Utility only works if you have  a Raid card.  I dont have a RAID card. I created the raid set using Disc utility.  I'm searching all over the net for a solution. I keep coming up with these same old posts here. Thought I'd leave a reply In the hopes somebody might be able to help.  Here's more about my problem:


  • mschwen Level 1 Level 1 (0 points)

    I had the same problem. The fix was easy. I just physically removed one of the hard drives in the raid, booted up the mac, opened disc utility, then removed the raid. Put the other hd back in, and your in business.

  • WizardHunt Level 1 Level 1 (10 points)

    Did you ever get this fixed? I have the same problem and get the same error. One guy said to physically remove one of the drives then reboot and go back into disk utility and remove the raid at that point. Did you try that and did it work?

  • kvanh Level 1 Level 1 (0 points)

    I had this problem as well. I'm currently on Mountain Lion 10.9.2. No matter what i did i could not get the disk to eject in Disk Utility or delete the RAID set. I had created the 2-drive striped RAID set in 10.8, and at one point had encrypted the disk, then removed the encryption. Not sure any of that is related.


    The log shows I got the following error:


    2014-03-29 11:38:01 -0500: Deleting RAID “TMData”

    2014-03-29 11:38:01 -0500:

    2014-03-29 11:38:01 -0500: Unmounting volume for RAID set DC62E024-130A-4105-993E-D5A9ABB340EB

    2014-03-29 11:38:01 -0500: Can’t unmount RAID set DC62E024-130A-4105-993E-D5A9ABB340EB to delete it

    2014-03-29 11:38:02 -0500: Error deleting RAID: Invalid attempt to unmount a whole disk containing a partition map.


    The only solution I came up with was to physically remove one of the raid drives (they were in a firewire enclosure). I could then erase the other drive in Disk Utility. I then put the removed drive back in. Disk Utility showed the RAID set as offline and I could delete it.


    After deleting it I recreated the RAID and am currently doing a secure erase writing 1 pass of zeros to the whole drive (just to make sure everything is read/writable).

  • Steve Pandol Level 1 Level 1 (65 points)

    I had an internal RAID 0 and had the same problem. What I did was drag the RAID to the trash. It still showed "online" but I could then erase each disk separately. When I did this, the RAID was gone and I was back to having two separate disks.

  • tvcoop Level 1 Level 1 (0 points)

    I had a mirrored RAID set between 2 Hitachi HDs running 10.6. I didn't set them up and have no experience with RAID sets, but I did have passwords as I'm the new administrator for my campus. One HD failed. I replaced it with a SSD drive. Auto rebuild was not already enabled, so I cloned Mavericks OS onto the SSD and even though my 2nd Hitachi HD was also locked and status "Online" I was able to right click on it and eject it from my desktop. Then I was able to use Disk utility to securely erase it. Responses on this page helped me get to this point, so I hope my response will help someone in the future.

  • dmltv Level 1 Level 1 (0 points)

    This also fixed the same issue I had with Mavericks 10.9.5


    I had previously installed it as a raid config, though updating third party software required me to configure it with 2 drives. One used for production and one used for testing updates.


    Reformatting one drive was successful, the second one was impossible until I used your little trick. It saved me opening up the mac. Thanks!