OWC's view on Fusion Drives ONLY being on 2012 Mac Minis

Discussion in 'Mac mini' started by eyepea, Mar 13, 2013.

  1. eyepea macrumors member

    Jul 20, 2012
    There is a lot of info out there on setting up a fusion drive in terminal, but OWC suggests it can ONLY be done through terminal in the OSX installed that COMES WITH a 2012 MM, otherwise it is not a fusion drive, but only a core storage group of drives. Can anyone confirm this?



    See the 'absolute requirement' comment on having a MM2012, and associated replies to the post.

    I have a 2012 i7 2.6ghz that I plan to build a fusion drive through the following method:

    Install SSD and HDD.
    Run terminal from a USB OSX 10.8 recovery disk.
    Build drive with commands as per the many posts available.
    Format the drive in Terminal.
    Reboot into the USB recovery disk again.
    Install a new copy of OSX via download.

    I will be deleting the OS that was shipped with the MM because I want to do a fresh install. I imagine the download of OSX on a MM2012 is the 'special' OSX that OWC refers to?

    Can anyone confirm the info (mostly in the posts at the bottom of the OWC page) about the fusion drive only fully working the way OWC suggests?

    Thanks in advance.

  2. paulrbeers macrumors 68040

    Dec 17, 2009
    I don't see where this is suggested in this article. Further, this article was written in November, before Fusion based iMacs were available. To make a further point, the Mac Mini is one of the only Macs with internal dual drives (at least standard dual drives anyway). I think we would have heard more by others who have cMBP's and Mac Pro's who have switched to Fusion drives if their fusion drive didn't work properly.
  3. eyepea thread starter macrumors member

    Jul 20, 2012
    Thanks for the info. It was this comment in the posts after the article that I was referring to.


    OWC Michael
    December 12, 2012 at 2:35 pm
    There’s been a lot of confusion about what exactly a Fusion drive is. When Apple introduced Lion, they added a logical volume manager (Core Storage) to the OS. The key factor to Core Storage is that it allows a single volume to span multiple physical disks. Which makes the Fusion drive possible, but it isn’t the only aspect.

    What makes the Fusion drive a Fusion Drive is the introduction of Automated storage tiering to mix. This has actually been around since 2005 on larger scale networks where the software moves data across different disk types and RAID levels in order to balance space, cost and performance requirements of a server. Prior to the automation software this type of data manipulation was done manually.

    Most of the terminal command setups we’ve seen online are only initiating that Core Storage volume. It needs the software to run the automated storage tiering to make it a true Fusion Drive. So far we’ve only seen that software component in the 2012 Mac mini models that ship with their specific build of 10.8.2
  4. benwiggy macrumors 68020

    Jun 15, 2012
    Even if it is true, I would anticipate that the mythical 10.8.3 will have the code.

    You will reinstall the OS because you're wiping the disk and creating a new volume.
    Otherwise, there would be no reason to do a fresh install on a brand new machine.

    Bear in mind that some people have had trouble with reinstalling 10.8 on Late 2012 hardware. There seems to be an error, even in using the Recovery Partition, in recognising the hardware as compatible.
  5. paulrbeers macrumors 68040

    Dec 17, 2009
    This. Right now the Mini (and probably the iMac as well) have custom builds of 10.8.2, and most likely 10.8.3 will be a unified build meaning all Macs would have the logic needed to do fusion properly (IF their assumption is correct). I still believe that if this were true, more would have been made of it in the 4 months since they posted, but then again I don't follow fusion threads much outside of the Mini.
  6. Mike in Kansas macrumors 6502a

    Mike in Kansas

    Sep 2, 2008
    Metro Kansas City
    If by "tiering" OWC means "moving blocks of data around to make best use of the SSD and HDD in a Fusion Drive array", I can verify that my home-built Fusion Drive on my 2008 iMac does just that. I'm running 10.8.2. By using iStat menus when launching and running apps, I am able to see how over time various apps and data (Aperture Library, iTunes, etc.) have been moved around between my internal SSD and externally-fused 2TB FW800 HDD. I also experience the high transfer rate of the first 4GB of data (due to SSD buffer) which then falls to HDD speeds like a stock FD. I have a 2.24GB FD array using 800GB of space, so my disk usage well exceeds my 240GB SSD.

    My usage and experience are similar to those captured in the detailed review that Anandtech.com did on a 2012 iMac with built-in FD.
  7. eyepea thread starter macrumors member

    Jul 20, 2012
    Based on the above comments I wonder if there is an easier way to check whether the fusion mechanism is working within osx? If it is not working in some DIY's some people may only have a fused core storage array. Effectively a JBOD setup.
  8. MatthewAMEL macrumors 6502


    Oct 23, 2007
    Orlando, FL
    CoreStorage reads the 'media type' flag. It automatically creates a Fusion Drive when you assign them to the same logical volume group.

    It's been a part of CoreStorage since Lion, just undocumented until Apple decided to demo it.

    CoreStorage handles lots of file system chores now. In addition to Fusion Drive, it is also responsible for FileVault 2.

    The whole point of Fusion Drive is to be transparent to the user. Right now, iStat or iostat are the only methods to see how the data is being moved around.


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