DavidMcCallie

Q: Can a Lion boot drive be part of an Apple Software RAID?

After many hours of head-banging, I now realize that Lion cannot be installed on a boot drive that is part of an Apple software mirrored RAID (early Mac Pro hardware, Snow Leopard.)  Something about a limitation that a RAID drive cannot be repartitioned to allow for the creation of the Recovery partition.  Sad, but so be it.

 

So, I plan to use SuperDouper! to copy my boot drive to a fresh, non-RAID drive, boot from that drive, and then and install Lion there. 

 

Once I have done that, will I be able to add the new Lion boot drive to a new Apple Software RAID mirror set?  Or is Lion simply not capable of being booted from a software RAID device?

 

Thanks in advance!

 

--david

Posted on May 3, 2012 11:51 AM

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Q: Can a Lion boot drive be part of an Apple Software RAID?

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  • by Kappy,

    Kappy Kappy May 3, 2012 11:54 AM in response to DavidMcCallie
    Level 10 (271,713 points)
    Desktops
    May 3, 2012 11:54 AM in response to DavidMcCallie

    You cannot add it to a RAID without destroying all the data on the drive, but you can create a RAID on which you can install OS X. Note that Lion cannot create a Recovery HD on a RAID array. Practically, you should not use a RAID as a startup volume.

  • by Bernie Case,

    Bernie Case Bernie Case May 3, 2012 11:57 AM in response to DavidMcCallie
    Level 1 (35 points)
    May 3, 2012 11:57 AM in response to DavidMcCallie

    Hi David,

     

    I'm using a striped AppleRAID device as my boot device here.  I basically did exactly what you're doing.  When I got a new Mac Pro, I used Super Duper! to clone my original Mac's hard drive to a new striped disk set I created.


    Can't use Lion Recovery with this, but I have a USB disk I use for that.

     

    See screenshot for my config...

     

    Screen Shot 2012-05-03 at 11.56.47 AM.png

  • by DavidMcCallie,

    DavidMcCallie DavidMcCallie May 3, 2012 12:08 PM in response to Kappy
    Level 1 (0 points)
    May 3, 2012 12:08 PM in response to Kappy

    Kappy,


    Thanks for the quick reply.

     

    Could you clarify why "...you should not use a RAID as a startup disk?"  I have been using a mirrored RAID configuration for years as my "main" drive (which I boot off of) and have had no trouble.  In fact, the mirror drive saved me once when the other side of the mirror failed.

     

    How would you propose using a mirror to protect your data, but have a non-mirrored boot drive?  What parts of the system would go where?

     

    Thanks.

  • by DavidMcCallie,

    DavidMcCallie DavidMcCallie May 3, 2012 12:11 PM in response to Bernie Case
    Level 1 (0 points)
    May 3, 2012 12:11 PM in response to Bernie Case

    Hi Bernie,


    Thanks for the advice. I am still a little confused.  What I was considering was to create a bootable Lion disk (with a recovery partition) and THEN convert the whole thing (including the recovery partition?) to a mirrored AppleRAID.  It sounds like that's not possible because of the way the Recovery partition works?  Do I have that right?

     

    If so, how did you create a Recovery Partition on a USB disk?  Can you point me to those instructions?

     

    Thanks!

  • by Kappy,

    Kappy Kappy May 3, 2012 12:17 PM in response to DavidMcCallie
    Level 10 (271,713 points)
    Desktops
    May 3, 2012 12:17 PM in response to DavidMcCallie

    RAIDs are intended to provide fast and large data storage or backup. They are not intended to be used as boot volumes. There are many potential problems that can arise with RAIDs that can cause catastrophic loss of data. Mirrored RAIDs provide no speed benefits, so they are best used to backup a startup volume rather than be used as a startup volume.

     

    On my Mac Pro I have a separate mirrored RAID set up that is used to back up my startup drive. Were one to use a RAID for backup, then this is the configuration I would suggest. It does require three drives: the startup drive and the two drives that make up the array.

  • by Kappy,

    Kappy Kappy May 3, 2012 12:19 PM in response to DavidMcCallie
    Level 10 (271,713 points)
    Desktops
    May 3, 2012 12:19 PM in response to DavidMcCallie

    Use the Lion Recovery Disk Assistant 1.0 to create a Recovery HD partition on a USB drive or flash drive. You must already have a Lion system with a valid Recovery HD partition to use the recovery disk assistant.

  • by Vicent,

    Vicent Vicent Oct 17, 2012 1:23 AM in response to DavidMcCallie
    Level 1 (0 points)
    Oct 17, 2012 1:23 AM in response to DavidMcCallie

    Hi David,

     

    I don't know if you are there yet.....

     

    I am in the same problem of you now!. I have a RAID boot partition in Snow Leopard and it is now when i wanto to update to Lion. So, at last, what was your solution for your situation?

     

    Thanks for reading me...

     

    VIcente

  • by DavidMcCallie,

    DavidMcCallie DavidMcCallie Oct 17, 2012 7:11 PM in response to Vicent
    Level 1 (0 points)
    Oct 17, 2012 7:11 PM in response to Vicent

    Hi Vicente,


    Basically I gave up and used a non-RAID drive as my boot drive.  Apparently you can't use RAID as a bootable system drive. I'm not sure, but I think this is because at boot time, the system does not have enough information to understand the RAID disk structures (using a software RAID anyway) and thus cannot read itself to complete the boot.  Not sure, but it's a convenient excuse


    Sorry!

     

    --david

  • by Vicent,

    Vicent Vicent Oct 18, 2012 1:02 AM in response to DavidMcCallie
    Level 1 (0 points)
    Oct 18, 2012 1:02 AM in response to DavidMcCallie

    Thanks for answering David....

     

    Ok. Got it. I will design a good recovery plan for the boot drive and I will install it without RAID.

    Thank you very much.

     

    Vicente

  • by Vicent,

    Vicent Vicent Oct 19, 2012 4:24 AM in response to DavidMcCallie
    Level 1 (0 points)
    Oct 19, 2012 4:24 AM in response to DavidMcCallie

    Hello Again,

     

    At the end, my process was something like (my memory is horrible):

     

     

    1. I take a image of a new installation of Lion in my macbook and I put in a USB external via clone.  And I connected this usb-drive to my box in my house.
    2. If you need to expand the volumen (my hd is bigger than the macbook's image) you will not be able to do it. You will need to delete & to create new GPT like this link: http://blog.kyodium.net/2010/11/increase-disk-and-partition-size-in.html. Works perfectly.
    3. Now, the big MUST: use the terminal, diskutil is your friend so after GPT, yes!, you already will be able to do a diskutil resizevolume <volumename> <newsize>. And later a diskutil repairvolumen <volumename> could be useful.
    4. At last, You will need to run a "diskutil appleraid create mirror <drive>" (command is not exact)

     

    It works. Tested. Done in 30 minutes in my case.

     

    So the alternative way to update should be (not tested):

     

    1. terminal in your snow leopard and sudo -s (it asks currect user pass).
    2. diskutil appleraid delete <raiddrive>, that convert your raid in two individual disk. No more raid but the data persist!!!. You will see two drives in the desktop.
    3. Choose one of them like disk to backup and the other like disk for updating
    4. boot with the disk for updating, it boots normal and install/update Lion. It should install.
    5. Now you use a boot rescue disk and open terminal, yes, there is a terminal there.
    6. sudo -s if you are not root. I don't remember it.
    7. You will need to run a "diskutil appleraid create mirror <drive>" (command is not exact)
    8. reboot and .... it boots. yeah!
    9. Now you will see the other ex-raid-disk (backup disk), now yu can add that other disk to raid via terminal or via disc/drive utility gui of OSX.
    10. may be it is interesting to do: diskutil appleRAID update AutoRebuild 1 raiddrive for a automatic rebuild when you have problems.

     

    Finally: no recovery disk in raid and no FileVault.

     

    Good luck!!!

     

    Vicente

     

    My results

    bash-3.2# system_profiler |grep "System Version"

          System Version: Mac OS X 10.7.5 (11G63)

    bash-3.2#

    diskutil appleraid list

    AppleRAID sets (2 found)

    ===============================================================================

    Name:                 DATOS

    Unique ID:            0DECFBDC-8375-47D4-B500-3611xxxxxx

    Type:                 Mirror

    Status:               Online

    Size:                 999.9 GB (999860862976 Bytes)

    Rebuild:              automatic

    Device Node:          disk4

    -------------------------------------------------------------------------------

    #  DevNode   UUID                                  Status     Size

    -------------------------------------------------------------------------------

    0  disk1s2   32985705-DECE-46CA-9EE9-D623B6Axxxx  Online     999860862976

    1  disk0s2   69C848B5-DB83-438E-968B-560E13D9xxxx  Online     999860862976

    ===============================================================================

    ===============================================================================

    Name:                 Macintosh HD

    Unique ID:            E5B95E3F-F600-4E7F-82F3-3D8D724xxxxx

    Type:                 Mirror

    Status:               Online

    Size:                 495.0 GB (494999994368 Bytes)

    Rebuild:              automatic

    Device Node:          disk5

    -------------------------------------------------------------------------------

    #  DevNode   UUID                                  Status     Size

    -------------------------------------------------------------------------------

    0  disk2s2   71774EF5-5EF9-4557-A2B6-455184Exxxx  Online     494999994368

    1  disk3s2   09CDD85C-5A58-4ABD-9B7A-A5AB4xxxx  Online     494999994368

    ===============================================================================

    bash-3.2#

  • by calipvp,

    calipvp calipvp Mar 2, 2014 10:02 PM in response to Vicent
    Level 1 (4 points)
    Mar 2, 2014 10:02 PM in response to Vicent

    My Results

     

    bash-3.2$ system_profiler | grep "System Version"

          System Version: OS X 10.9.2 (13C64)

    bash-3.2$ diskutil appleraid list

    AppleRAID sets (1 found)

    ===============================================================================

    Name:                 Mavericks OS X

    Unique ID:            C97EDEF2-5E60-4460-B891-70935507422D

    Type:                 Stripe

    Status:               Online

    Size:                 999.5 GB (999527546880 Bytes)

    Rebuild:              manual

    Device Node:          disk5

    -------------------------------------------------------------------------------

    #  DevNode   UUID                                  Status     Size

    -------------------------------------------------------------------------------

    0  disk1s2   9CE5E65F-88F5-47FD-81CB-CF7B4A09FDEC  Online     499763773440

    1  disk0s2   B7BB7A80-D737-41ED-9117-0B3583864379  Online     499763773440

    ===============================================================================

    bash-3.2$

     

     

    I know, I know it's Raid 0.... but it's really fast.  I can always rebuild my OS drive as all my data resides on other drives.