OS X Mountain Lion confirmed to support Fusion Drive on legacy Macs

Posted:
in General Discussion edited January 2014
A developer on Wednesday revealed that the Fusion Drive support built into OS X Mountain Lion is compatible with a makeshift hybrid storage device, proving the technology can be used with Macs which didn't come preconfigured to take advantage of the feature.

Fusion Drive


In a post to Tumblr, developer Patrick Stein unofficially confirmed that Mountain Lion provides Fusion Drive support for current Macs, as he was able to "build" a hybrid drive compatible with Apple's new storage technology.

When Apple announced its new Fusion Drive hybrid storage solution alongside the redesigned iMac earlier this month, it noted that OS X Mountain Lion would be able to operate the system without the need to update. This prompted some to question whether existing hybrid drives would work with current Macs not configured with Apple SSD and HDD combination, as the statement suggested support for the technology was already embedded in the operating system's code.

Using the Terminal version of disk utility, Stein was able to setup a solid state drive and a separate hard drive so that OS X recognized both as a single logical volume, which is basically what Fusion Drive promises. Just as Apple's Fusion Drive configures an SSD and an HDD into a single volume, Stein used an SATA-connected 128GB SSD and USB-attached 750GB HDD in his working solution.

In order to build a single logical volume, the developer used Core Storage, the OS X feature that links two separate storage units into one volume group, to join the SDD and HDD. Next, Stein created a 466GB HFS+ volume, otherwise known as Mac OS Extended, to facilitate file creation and transfer.

"Now in DiskUtility the individual disks no longer show, but the Logical Volume (LV) shows as one disk," Stein said. "Part One is finished, we?ve created a single Volume consisting of a SSD and a HDD."

To test whether the jury-rigged setup was being operated as a Fusion Drive, Stein created a number of directories with files equating to 140GB of data by using the mkdir and mkfile commands. During the process, data was funneled to the SSD until the 120GB mark, at which point the remaining files were written to the HDD in directories 11 to 13.

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Point at which files begin to be written to HDD. | Source: Patrick Stein (jollyjinx) via Tumblr


Next, Stein used the dd command to force reads of the data located on the HDD, an activity that Fusion Drive uses to determine which files are heavily accessed and should thus be relocated to the faster SSD. After stopping the read process, Stein used iostat to monitor whether any files were transferred to the SSD.

Immediately following the dd process, the system began dumping data from the SSD to the HDD, stopping after about 14GB of copying. Stein then attempted to readout data from directories 11 to 13, and at first found they were still located on the HDD. However, after about an hour of reads the files were being accessed from the SSD, meaning Fusion Drive had transferred the data successfully.

HDD Access
First reads show no HDD to SSD file transfers (top). After an hour the SDD is being accessed (bottom),
confirming that Fusion Drive is active.


While the informal test does prove that Fusion Drive is active and usable on older Macs, the process of configuring the hybrid storage devices is definitely not plug-and-play. It remains to be seen if Apple will offer Mac owners an easy way to configure their own components without having to run Terminal and command line code.
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Comments

  • Reply 1 of 37
    Very cool. I've got a similar setup in my MBP having replaced its optical drive with a SSD. The difference is that I decide which files go where and I have symlinks set up to support this (so that, for example, my Windows 7 VM virtual drive lives on the SSD while my other, less frequently used VMs live on the HDD along with my other documents and media files).

    I wonder if there's a way to force particular files to 'stick' to a particular physical drive with this setup. With my Mac OS X install and my (heavily-used Windows 7 VM), my computer boots in a matter of seconds, as does my VM, and my frequently-used Mac applications launch with nary a bounce in the dock. I *love* it!
  • Reply 2 of 37
    solipsismxsolipsismx Posts: 19,566member
    While Apple's Fusion Drive hardware is a hybrid drive with SSD and HDD bundled in one package, Stein used an SATA-connected 128GB SSD and USB-attached 750GB HDD in his working solution.

    That is incorrect. It's not a hybrid drive it's two discreet drives, one an SSD and one a HDD being made into one virtual drive by the OS.
  • Reply 3 of 37

    Quote:

    Originally Posted by djames4242 View Post



    Very cool. I've got a similar setup in my MBP having replaced its optical drive with a SSD. The difference is that I decide which files go where and I have symlinks set up to support this (so that, for example, my Windows 7 VM virtual drive lives on the SSD while my other, less frequently used VMs live on the HDD along with my other documents and media files).

    I wonder if there's a way to force particular files to 'stick' to a particular physical drive with this setup. With my Mac OS X install and my (heavily-used Windows 7 VM), my computer boots in a matter of seconds, as does my VM, and my frequently-used Mac applications launch with nary a bounce in the dock. I *love* it!


     


    I was thinking about doing this myself. Do you have the SSD plugged into the HDD port, and the HDD plugged into the Optical port, the other way around, or does it make a difference? I've only recently considered doing this so I don't know much about the pros and cons of different configurations.

  • Reply 4 of 37
    Apple's new feature is NOT a Hybrid drive. It is NOT special Hardware at all.

    It combines a stand-alone SSD with a stand-alone SATA Hard Drive using a feature previously only available on mainframe-class computers known as Hierarchical Storage Management.

    This Tiered Storage moves entire Files (not just blocks) back and forth from faster to slower storage as their frequency of use changes. This gives overall drive performance that is much closer to that of the faster of the two drives.

  • Reply 5 of 37
    focherfocher Posts: 638member
    myopicman wrote: »
    Apple's new feature is NOT a Hybrid drive. It is NOT special Hardware at all.
    It combines a stand-alone SSD with a stand-alone SATA Hard Drive using a feature previously only available on mainframe-class computers known as Hierarchical Storage Management.
    This Tiered Storage moves entire Files (not just blocks) back and forth from faster to slower storage as their frequency of use changes. This gives overall drive performance that is much closer to that of the faster of the two drives.
    Nope. The independent testing showed it works at the block level.
  • Reply 6 of 37


    Edited slightly (only on the forum article) in light of Fusion Drive not (and never having been) specialized hardware. If it's still confusing or unclear, I can make further changes.

  • Reply 7 of 37
    Lets take the most obvious candidate: I have a new iMac (Purchased Aug 12') with the extra SSD upgrade from Apple. Since my iMac came factor shipped with both drives installed, can I somehow easily turn that into a fusion drive?

  • Reply 8 of 37
    ktappektappe Posts: 759member

    Quote:

    Originally Posted by jrossjr View Post



    Lets take the most obvious candidate: I have a new iMac (Purchased Aug 12') with the extra SSD upgrade from Apple. Since my iMac came factor shipped with both drives installed, can I somehow easily turn that into a fusion drive?


    "Somehow"? Yes. "Easily"? No. There is no GUI to do this; you must get your hands dirty and enact it from the command line as Patrick did. (http://jollyjinx.tumblr.com/post/34638496292/fusion-drive-on-older-macs-yes-since-apple-has)  It's not actually that hard if you're comfortable with Terminal and the diskutil command.  And you only need to do Part 1 of his procedure; then you install your OS onto the logical volume that you created.  Use it as usual, letting Core Storage do all the work behind the scenes.

  • Reply 9 of 37


    'Hybrid' drives have already been in Windows (and Linux) machines for a bit.  Nothing too special really. 


     


    And they really are just 2 separate hard drives, working as one with a little bit of partitioning magic... 

     

  • Reply 10 of 37
    analogjackanalogjack Posts: 1,064member


    This is cool, I was planning on getting rid of my 3.4GHz imac at the next haswell update and this will make it easier to sell at a good price as it can make use of this new technology. An external SSD can be combined with the internal HD.

  • Reply 11 of 37
    apple ][apple ][ Posts: 8,436member


    I've been using a combination of internal SSD for the OS and other important programs, and I'd put all large files and stuff like movies and games on external, regular drives. I've been satisfied with that combo, since going 100% SSD is still too expensive, especially if you have terrabytes worth of stuff.


     


    This Fusion Drive concept seems interesting, but I have to test it out for myself to see how well it works for me. I didn't mind manually determining what went on SSD and what went on spinning drives, the Fusion Drive seems to take away that choice.


     


    Also, I wonder how Time Machine will work with the Fusion drive, will it back up to two separate Time Machine volumes now?

  • Reply 12 of 37
    apple ][apple ][ Posts: 8,436member


    And speaking of SSD's, I just received an email in my inbox.


     


    One of today's shell shockers is an Intel 330 180GB for the price of $99.99. I guess that I'm going to be forced to order one. I have an older Intel SSD from before, and I've been pretty happy with that one. Who can resist at that price?image

  • Reply 13 of 37

    Quote:

    Originally Posted by Cash907 View Post


     


    I was thinking about doing this myself. Do you have the SSD plugged into the HDD port, and the HDD plugged into the Optical port, the other way around, or does it make a difference? I've only recently considered doing this so I don't know much about the pros and cons of different configurations.



     


    I've also modded my late 2011 MBP. I installed the SSD in the hard drive bay because the SATA connection is a full 6 Gigabit Negotiated Link Speed and moved the hard drive to the optical drive bay which has a 3 Gigabit connection. I used a cheap adapter which I bought from from a Chinese firm on Ebay. Even configured as two separate drives, the speed increase is far greater than any processor upgrade. Battery life is way better and Time Machine will backup and restore both drives without a problem. Now if you want to restore just one drive, that gets a little trickier as you have to enter Time Machine and pick out the individual drive to restore. You'll also need a small program named "Trim Enabler" by Oskar Groth (Groths.org/Cindori.se) to keep the SSD in good shape.


     


    Google, Yahoo, or Bing around the web; there's plenty of info on how to do this.

  • Reply 14 of 37

    Quote:

    Originally Posted by ktappe View Post


    "Somehow"? Yes. "Easily"? No. There is no GUI to do this; you must get your hands dirty and enact it from the command line as Patrick did. (http://jollyjinx.tumblr.com/post/34638496292/fusion-drive-on-older-macs-yes-since-apple-has)  It's not actually that hard if you're comfortable with Terminal and the diskutil command.  And you only need to do Part 1 of his procedure; then you install your OS onto the logical volume that you created.  Use it as usual, letting Core Storage do all the work behind the scenes.



     


    I look forward to the day, which I'm sure will come not so very long from now, when somebody will create a small app to let anyone activate Mountain Lion's Fusion capabilities. Now I know what I want from Santa for Christmas image ! 

  • Reply 15 of 37
    [QUOTE]I was thinking about doing this myself. Do you have the SSD plugged into the HDD port, and the HDD plugged into the Optical port, the other way around, or does it make a difference? I've only recently considered doing this so I don't know much about the pros and cons of different configurations.[/QUOTE]

    I have tried both and it didnt seem to make a difference for me. I guess it depends on your model of mac, but most have the same bandwidth on both ports (check with the excellent Mactracker app from the app store).

    Symlinks are a good way of working and i have had no trouble with them, but they can be a bit confusing when it comes to backing up, etc. There is a great little extension for making symbolic links without using Terminal here: http://seiryu.home.comcast.net/~seiryu/symboliclinker.html

    Especially if you start out with a large hard drive full of stuff you will have to do some shuffeling around with another external hard drive. Make a full image backup before doing anything and keep regular backups! In the end I had the OS and applications on the SSD and symlinked Desktop, Music, Downloads, etc. and it worked amazingly.

    If only the retina MBP had an optical drive I could remove :D /s
  • Reply 16 of 37


    BYO Fusion UP AND RUNNING


     


    It is doable, but as stated, you will have to get down and dirty with terminal and diskutil.


     


    I have been running an 120GB OWC SSD and a 750GB Scorpio Black in my MBP for about a year now, but I had manually moved things to where I wanted them and then used symbolic links so that the OS, TM and my applications behaved as though it was a single drive (ie it appeared that everything was on the SSD).


     


    So, when arstechnica reposted jollyjinx's blog regarding a BYO Fusion, I took the plunge.


     


    I first reconstituted my split drive scenerio back to a single bootable external drive. After ensuring that I could indeed boot from the reconstituted drive and that all my data was intact (I also had a TM backup just in case).


     


    I used diskutil to create a single core storage logical drive from the two physical drives (FYI both mounted internal on SATA). I then partitioned the single logical drive into two partitions, one for swap/hibernation (40GB) with the remainder going to the other partition (created the main partition FIRST). At this time, you have to use diskutil core storage create volume to partition as the Disk Utility application indicates that the newly minted Core Storage drive is in a locked status (ML's Disk Utility has not been rewritten yet to understand Fusion) .


     


    With the single logical drive created, partitioned and formatted, I did a clean download of Mountain Lion and installed it to the main partition on the logical drive. Once ML installed and booted, I did a restoration from the reconstituted copy of my original environment. All came back up after the restoration.


     


    Compared to my manually split, but unified (ie symbolically linked) file system, this new core storage version seems to be performing similarly. At first it was not as crisp, but that was to be expected as core storage still had to perform its magic of moving things around (an ongoing, never ending process). Finally I moved the hibernation file over to the separate partition and created a symbolic link in the main directory to the new location. Then I modified the appropriate launch daemon to point swap over to the new partition and finally using SetFile I hid the swap partition Upside, a return to the traditional single drive mac mentality. The downside...turning control over to core storage and hoping it all works as indicated. But in the end, those classic words do seem to apply. IT JUST WORKS. David

  • Reply 17 of 37
    focherfocher Posts: 638member
    mikeb85 wrote: »
    'Hybrid' drives have already been in Windows (and Linux) machines for a bit.  Nothing too special really. 

    And they really are just 2 separate hard drives, working as one with a little bit of partitioning magic... 

     
    This is quite different than a hybrid drive, which integrates some NAND flash for caching, or Intel's SRT. Fusion Drive is essentially Apple's version of tiered / hierarchical storage. And the benefits are far greater. Hybrid drives in particular haven't shown themselves to provide much greater performance benefits.

    Besides, a hybrid drive doesn't require any specific OS support as it's integrated at the drive's firmware level.
  • Reply 18 of 37
    jragostajragosta Posts: 10,473member
    mikeb85 wrote: »
    'Hybrid' drives have already been in Windows (and Linux) machines for a bit.  Nothing too special really. 

    And they really are just 2 separate hard drives, working as one with a little bit of partitioning magic... 

     

    It's pretty easy to tell the people who can't be bothered to learn how the technology works before posting. "Fusion is just a hybrid drive" comments are one sure sign of this.

    Fusion is not a hybrid drive. Hybrid drives have worked on Macs for years, as well. Fusion is a tiered storage model - which is NOT available on Linux or Windows.

    Now, until there are some published reports of performance, it's hard to say how well it will work. In my experience, hybrid drives don't come close to the performance claims made by their vendors. Only time will tell if Fusion is better, but it certainly works well in big iron installations.
  • Reply 19 of 37


    Not only does Fusion (actually Core Storage) implement a tiered storage model, it operates at the block level as clearly demonstrated by jollyjinx (second post).  When you have large files where only a subsection of a file gets routine updates (think Parallels VM), ONLY the blocks of data that change routinely get promoted to the SSD.   

  • Reply 20 of 37
    conrailconrail Posts: 489member

    Quote:

    Originally Posted by waybacmac View Post


     


    I look forward to the day, which I'm sure will come not so very long from now, when somebody will create a small app to let anyone activate Mountain Lion's Fusion capabilities. Now I know what I want from Santa for Christmas image ! 



    Hopefully this will be like Bootcamp.  When the first Intel macs came out, people were hacking them to run Windows on a separate partition.  Eventually, Apple made this an official feature.  Making Fusion a "real" feature would be a huge plus to the Mac Mini and Mac Pro crowd, who have machines that "officially" have multiple user accessible drive bays, as well as plenty of people with Macbook Pros and Imacs.

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