Custom Fusion Drive Creation

Discussion in 'Mac Accessories' started by mawyatt1, Sep 25, 2014.

  1. mawyatt1 macrumors member

    Joined:
    Jul 12, 2014
    Location:
    Clearwater, Fl
    #1
    Can a custom Fusion Drive be created externally on Thunderbolt or USB 3.0 interfaces? I would like to create custom Fusion Drive that has more than 4GB of the SSD available to directly write to. The 4GB is what the Apple Fusion Drive creates for the SSD direct writes. Something like 32 or 64GB would work better for my needs.

    I know LaCie has a new Thunderbolt II drive that can hold a custom SSD as well as the standard hard drives. Don't know if this can be configured as a custom Fusion Drive though. Another possibility would be to use a SSD (Samsung) and standard hard drive in a Thunderbolt enclosure and configure as a Fusion Drive.

    Thanks in advance,

    Mike
     
  2. AllergyDoc macrumors 65816

    AllergyDoc

    Joined:
    Mar 17, 2013
    Location:
    Utah, USA
    #2
    I've read here where it can, Mike. Unfortunately I can't tell you how to do it, but I'm sure someone will come along who can.
     
  3. marzer macrumors 65816

    marzer

    Joined:
    Nov 14, 2009
    Location:
    Colorado
    #3
    You can pretty much combine any two drives on any interface to create a fusion. I've done it on SATA, Thunderbolt, USB and even FireWire. As long as the system sees both drives as mass storage devices you can combine them into a fusion volume. However, for all my mucking about with fusion drives, I've not come across any Corestorage parameter that lets you change the size of the read/write buffer.
     
  4. mawyatt1 thread starter macrumors member

    Joined:
    Jul 12, 2014
    Location:
    Clearwater, Fl
    #4
    Can these be created directly from the Apple disk utility? That's interesting that the R/W buffer would be fixed and not allowed to change. This would mean the only long term benefit of a larger SSD would be the larger read space, since the write space is fixed at 4GB. Hope someone has cracked this, as 4GB is not enough space for what I have in mind.

    Thanks for the information,

    ----------

    With all your Fusion work, do you feel this is worthwhile over working directly from the SSD and then copying files over to the standard HD. I like the idea of the Fusion doing this in the background for you.

    Thanks,
     
  5. marzer macrumors 65816

    marzer

    Joined:
    Nov 14, 2009
    Location:
    Colorado
    #5
    You can't create a DIY fusion drive using the graphical Disk Utility. Instead, you use the 'diskutil' command from a terminal window to create the corestorage logical volume containing the two drives as a single fusion volume.

    The long term benefit of a larger SSD as part of a fusion drive is also that it can contain more of you applications and and more of your often-used user data for quicker read/write access.

    Of course, if you have a need for handling massive files that exceed the buffer space, you might consider not using fusion. Keep you're SSD as a single volume so your current work file is in no threat of being off loaded to a slower hard drive.
     
  6. mawyatt1 thread starter macrumors member

    Joined:
    Jul 12, 2014
    Location:
    Clearwater, Fl
    #6
    Is there a site you could point to that discusses this Fusion setup from the terminal?

    Thanks,

    Mike
     
  7. Cojm macrumors member

    Joined:
    Sep 19, 2014
  8. marzer macrumors 65816

    marzer

    Joined:
    Nov 14, 2009
    Location:
    Colorado
    #8
  9. hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #9
    Yes, you can do that. I would however, keep them in the same enclosure to avoid disconnects, but that is just my paranoia.

    I have built Fusion external drive systems using the LaCie "Little Big Disk Thunderbolt" enclosure, a Pegasus J4 Thunderbolt enclosure, and a OWC ThunderBay IV enclosure. They all worked just as expected.
     
  10. mawyatt1 thread starter macrumors member

    Joined:
    Jul 12, 2014
    Location:
    Clearwater, Fl
  11. mawyatt1 thread starter macrumors member

    Joined:
    Jul 12, 2014
    Location:
    Clearwater, Fl
    #11
    Another question. Has anyone made a Fusion drive from the LaCie Thunderbolt 2 Big enclosures by replacing one of the hard drives with a Samsung SSD?

    LaCie also has a new Thunderbolt enclosure that supports a special SSD that looks like it's made for using as a Fusion drive. I haven't seen any reviews though.

    Thanks,

    Mike
     
  12. g4cube macrumors 6502a

    Joined:
    Apr 22, 2003
    #12
    http://www.barefeats.com/hard191.html for a review of the new LaCie d2, and discussion of turning it into a Fusion drive.

    I've made a Fusion drive with the original Little Big Disk, replacing one of the 2 HDD with a Samsung Evo 150GB SSD.
     
  13. mawyatt1 thread starter macrumors member

    Joined:
    Jul 12, 2014
    Location:
    Clearwater, Fl
    #13
    Thanks so much. How did you DIY Fusion drive work?
     
  14. g4cube macrumors 6502a

    Joined:
    Apr 22, 2003
    #14
    Works fine in the Little Big Disk, but I did it more as an investigative effort to see how it might work. Performance is similar to what Apple ships as both rely on SATA-3 SSD.

    The new LaCie d2 is more intriguing as described in the barefeats.com write-up, as a PCIe SSD is used in stead of a SATA-3 SSD.

    Too many people are obsessing over performance without understanding where performance improvements will truly help in everyday efforts.

    To me stability and reliability is important. The external Little Big Disk Fusion drive is great if I want to rely on an external boot drive. All contained in one external device. Others have built Fusion configurations combining an internal drive with an external drive, or 2 separate external drives, without understanding that this can create an issue if one of the devices goes missing or bad.

    Still others obsess about performance when their use is primarily browsing or word processing.

    In any case, Fusion is still a work in process for Apple as the primary Disk Utility application will not handle Fusion configuration for everyone; restricted to Macs originally shipping with a Fusion configuration. Command line diskutil is what is required for DIY people.

    Finally, please remember to backup if you are experimenting with Fusion.
     
  15. mawyatt1 thread starter macrumors member

    Joined:
    Jul 12, 2014
    Location:
    Clearwater, Fl
    #15
    Agree about reliability and use. My primary goal is for intensive photographic use. I have 2 LaCie 2 Bigs for external storage and a USB3 WD for Time Machine for my Mac Pro and a Firewire LaCie as Time Machine for my MacBook Pro. Even though the 2 Bigs are RAID 0 and can do ~300MB/s R/W under BlackMagic they are kind of slow on startup and random files. This is where the SSD drives shine, and where a large Fusion drive might make sense for me. The fast random speed and startup with large capacity seems ideal for my work flow. I know the 4GB write limit might get in the way, wish there was a way to use a larger size maybe up to 32GB. I guess without going ahead and actually getting the LaCie d2 with SSD I won't know how well it would work for my work flow.

    I just replaced the 256GB SSD in my MBPr with a Transcend 960GB and that made an improvement. My Mac Pro SSD is very fast but I don't want to store work files on this internal drive, they go to the external drive(s).

    Thanks for all the help,

    Mike
     
  16. g4cube macrumors 6502a

    Joined:
    Apr 22, 2003
    #16
    An SSD is excellent for random access. Much better than an HDD.

    Remember that with a Fusion drive, the OS will automatically move frequently used files to the SSD portion of the drive, and less frequent files to the HDD portion.

    It may help you.

    Now, if it works for you, consider 2x1TB SSD if your needs are less than 2TB, or give the Fusion a try to see if it really makes a difference with your work flow.

    The 1TB Little Big Disk v2 with PCIe SSD will be your fastest for random access as well as sequential file access.

    Look at AJA disk test to give you a better idea concerning small file random access.
     
  17. vga4life macrumors 6502

    Joined:
    Jun 16, 2004
    #17
    I posted something along these lines in the iMac board last week after I read the reviews of the LaCie d2 SSD upgrade module. It might be possible to reach the theoretical max IO performance of the current generation of iMac by creating a RAID0 stripe across the internal PCIe SSD and a thunderbolt attached PCIe SSD.

    Consider the following configuration:
    • Late-2013 iMac with fusion drive (i.e. an internal 128GB PCIe SSD and 1 or 3TB magnetic HD)
    • LaCie d2 TB2 enclosure with SSD upgrade (i.e. a 128GB PCIe SSD and a 3 - 6 TB magnetic HD)

    Then do something like the following procedure:

    1. Boot from external drive.
    2. Split the internal fusion drive
    3. Create 100GB partitions on each 128GB SSD, leaving the rest unallocated (force extra overprovisioning for consistent performance.)
    4. Create appleRAID stripe across the two 100GB SSD partitions.
    5. Partition and format internal HD as desired
    6. Partition and format external HD as a single large volume for TimeMachine.
    7. Install OSX on 200GB dual-SSD stripe, and go to town.

    AFAICT, this configuration would get you a lot of nice things: something approaching the very fastest system/work volume it is possible to achieve on an iMac; an internal drive for bulk/nearline storage, and a TimeMachine volume to backup everything.

    It's interesting enough that I'd consider dropping the $600 for a d2 + SSD module, except I don't know if a raid stripe across internal and TB-attached devices would be a sufficiently stable config.
     
  18. MacRobert10 macrumors 6502

    Joined:
    Nov 24, 2012
    #18
    You can actually use Core Storage, which is what the Fusion uses, to make a virtual drive out of a bunch of different drives of different types with different interfaces.

    How do I know? I did it. I have a home made Fusion in one of my systems and before I went the full gammit on it I took several old USB and Firewire drives to create a core storage volume just to test it out. I wanted to see if it could be done and if done, how reliable was it.

    It worked. I then created a Fusion drive using an internal SSD and an external Firewire (because that's what the system had) with no problems at all. The unit is a desktop unit so having an external connected to it all the time is no big deal.
     
  19. g4cube macrumors 6502a

    Joined:
    Apr 22, 2003
    #19
    Just need to make sure all drives that are part of the Fusion configuration are present and available. Best to be sure of connections and power.

    The more connections you have, the more chance you have for something to go wrong, so keep power and connections secured.
     

Share This Page