DIY Fusion Drive Not Working -> Did you test your's?

Discussion in 'iMac' started by MacBj, May 20, 2015.

  1. MacBj macrumors newbie

    MacBj

    Joined:
    Dec 9, 2014
    Location:
    Switzerland
    #1
    Hey Folks,

    i just followed the instructions to setup a fusion drive....

    due i had a slow performance after reinstall, i checked if my Fusion Drive
    was working rigth, and in terminal it said it looked like fusion, but did not work like one (see below)

    Question:

    1. Did someone check his DIY Fusion with "diskutil cs info -your LVG-"
    2. I've splitted my SSD in 2 partitions for OS X and Bootcamp,

    NOW: Buy doing the setup of a Fusion drive, do i have to indicate
    the full disk, like diskutil cs create MyName /dev/disk1 /dev/disk2

    or can i give in like dev/disk1s2 dev/disk2 ?

    i wonder if that's the point, someone had the same problem?

    now here's the terminal output:

    diskutil cs list
    CoreStorage logical volume groups (1 found)
    |
    +-- Logical Volume Group 8EB8E8E9-ACAD-4978-A8D9-0A14C8B9C932
    =========================================================
    Name: bigfast
    Status: Online
    Size: 1002167910400 B (1.0 TB)
    Free Space: 14454784 B (14.5 MB)
    |
    +-< Physical Volume 55638A6C-18A8-4D70-8FCA-BF150B83F462
    | ----------------------------------------------------
    | Index: 0
    | Disk: disk1s2
    | Status: Online
    | Size: 749812400128 B (749.8 GB)
    |
    +-< Physical Volume EC35DAA0-0507-40D5-9EF4-E6884CDB03D5
    | ----------------------------------------------------
    | Index: 1
    | Disk: disk0s2
    | Status: Online
    | Size: 252355510272 B (252.4 GB)
    |
    +-> Logical Volume Family 78310798-6B36-442D-B8A2-D9FFA1C023C1
    ----------------------------------------------------------
    Encryption Status: Unlocked
    Encryption Type: None
    Conversion Status: NoConversion
    Conversion Direction: -none-
    Has Encrypted Extents: No
    Fully Secure: No
    Passphrase Required: No
    |
    +-> Logical Volume D9C39CEC-275D-43F0-80E3-A3801EAEFA89
    ---------------------------------------------------
    Disk: disk2
    Status: Online
    Size (Total): 1001515794432 B (1.0 TB)
    Conversion Progress: -none-
    Revertible: No
    LV Name: MacFusion
    Volume Name: MacFusion
    Content Hint: Apple_HFS

    looks ok,

    now check this out:

    diskutil cs info 8EB8E8E9-ACAD-4978-A8D9-0A14C8B9C932
    Core Storage Properties:
    Role: Logical Volume Group (LVG)
    UUID: 8EB8E8E9-ACAD-4978-A8D9-0A14C8B9C932
    LVG Name: bigfast
    LVG Version: 1
    LVG Size: 1002167910400 B
    LVG Free Space: 14454784 B
    LVG Status: Online
    LVG Sparse: No
    Fusion Drive: No


    so it looks like a spanned disk or something

    someone's got a hint?

    Thanks
     
  2. hfg, May 20, 2015
    Last edited: May 21, 2015

    hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #2
    I have built Fusion drives with partitioned disks many times with no problems.

    I simply used diskID values like this when creating the join:

    ...... (use diskutil list to get volume IDs)
    diskutil cs create MyFusion disk1s2 disk2
    ...... (use diskutil cs list to get lvgUUID or copy from above output)
    diskutil coreStorage createVolume lvgUUID jhfs+ "Macintosh FusionHD" 100%



    I just built a Fusion drive that I am currently on and it is reporting info as:

    diskutil cs info F594D17A-E047-43AF-BCD8-CD8890B9CEC3
    Core Storage Properties:
    Role: Logical Volume Group (LVG)
    UUID: F594D17A-E047-43AF-BCD8-CD8890B9CEC3
    LVG Name: Fusion
    LVG Version: 1
    LVG Size: 2011724152832 B
    LVG Free Space: 90112 B
    LVG Status: Online
    LVG Sparse: Yes
    Fusion Drive: Yes


    [The above example info output is not actually a split partitioned drive, but one I created just a couple of hours ago using a 512GB SSD and a 1.5TB 2.5" hard disk in an external LaCie "Little Big Disk" Thunderbolt enclosure attached to a Mac Mini]

    Here is an article I have found useful:
    http://www.macworld.com/article/2014011/how-to-make-your-own-fusion-drive.html


    -howard
     
  3. rbart macrumors regular

    Joined:
    Nov 3, 2013
    Location:
    France
    #3
    It's important to start you LVG name with a capital letter, for example "Fusion".
    If not, it won't work as a fusion drive, it will behave like a big disk without fusion optimizations.
     
  4. MacBj thread starter macrumors newbie

    MacBj

    Joined:
    Dec 9, 2014
    Location:
    Switzerland
    #4
    Rbart,

    that with the big letter did the trick, that was the point, i never had that problem before,

    it seems i was always lucky in writing the Names with a Capital Letter, execpt this time, now it's back on track and i'm just restoring my backup

    Thank's for your useful reply's folks and merci en France.

    Salutations


    Björn

    :):):):):):):):):):):)
     
  5. hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #5
    That is very interesting ... where did you find that information?

    I guess I have just been very lucky since I always name my LVG "Fusion" with a capital "F" by default.
     
  6. MacBj thread starter macrumors newbie

    MacBj

    Joined:
    Dec 9, 2014
    Location:
    Switzerland
    #6
    i guess in Terminal capital letter makes the diffrence ;-) to be or not to be, also the first time i changed my standard naming,

    Normaly you just feel that your fusion is working.... ;-)

    yeah would be nice to know...
     
  7. rbart macrumors regular

    Joined:
    Nov 3, 2013
    Location:
    France
    #7
    I have found a post somewhere explaining that.
    http://forums.macrumors.com/showthread.php?t=1816538
     
  8. hfg macrumors 68040

    hfg

    Joined:
    Dec 1, 2006
    Location:
    Cedar Rapids, IA. USA
    #8

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