MacBook Pro and the hot new thing: Paired Storage

MacBook Pro and the hot new thing: Paired Storage

Summary: One hot topic in storage right now is "paired storage," or the combined use of an HDD (hard disk drive) and SSD (solid-state drive), aka a flash drive. A third-party upgrade kit lets owners of the MacBook Pro give this advanced storage architecture a spin.

TOPICS: Apple, Hardware, Storage

One hot topic in storage right now is "paired storage," or the combined use of an HDD (hard disk drive) and SSD (solid-state drive), aka a flash drive. A third-party upgrade kit lets owners of the MacBook Pro give this advanced storage architecture a spin.

Some may confuse paired storage with hybrid hard drive technology that was announced a number of years ago. It's different. The hybrid drive incorporates a flash module inside the HDD mechanism. One the other hand, paired storage uses separate flash and hard disk drives simultaneously. This setup can mitigate the performance hit with using just HDDs and the lower capacities found in higher-performing SSDs.

Storage analysts Coughlin Associates and Objective Analysis last week released a joint report on paired storage: HDDs and Flash Memory:  A Marriage of Convenience. According to the authors' projections, paired storage will be found in 53 percent of desktop computers in 5 years and in 25 percent of notebooks in the same time period. They also predict "fat tablets" that will incorporate paired storage.

Other World Computing offers its OWC Data Doubler kit for the MacBook Pro, which lets owners swap out the optical drive and install either a second hard drive or a SSD. The company also sells the SSDs and HDD upgrades. Users can also create a software RAID array with the drives.

This custom engineered black anodized aluminum bracket with attached PCB circuit board comes ready to mount any 9.5mm tall 2.5" SATA hard disk drive and even Solid State Drives.

Because it's connected to the internal SATA connector, the drives are setup and partitioned with Apple's Disk Utility that comes with Mac OS X.

Currently, there's no special sauce in Mac OS X to support paired storage — yet. It's an obvious target for the future. Of course, just booting from an SSD brings plenty of performance.

I asked Robert Peglar, senior fellow at storage vendor Xiotech Corp. and SNIA board member, about where OS makers (Apple, Microsoft and Linux vendors) might target to boost performance on notebooks.

For example, I wondered if enterprise storage optimization techniques such as Fully Automated Storage Tiering (FAST) and continuous adaptive data placement (CADP) might find their way into notebook paired storage systems.

He suggested that boot-up was the best place to start.

At the consumer level, what is required is a very good sense by the distro vendor of what files are critical — especially files which are read-dominant — to be placed in SSD.  Boot is a good example of read-dominant workload, as files are read into memory in very small chunks — sometimes only 512 bytes at a time due to BIOS compatibility — and either executed (executables) or kept resident (device drivers, library routines, etc.)

Speed of boot is important to many consumers.  Beyond that, during normal operation, system-critical files which are read often are good candidates for SSD usage, and the OS must keep track of which files are 'hot'.

However, FAST and CADP were overkill, Peglar said. But for different reasons. FAST analysis of workload is performed over hours of time and can involve large "slices" of a drive.

Many are under the impression that such techniques are 'automatic' or otherwise 'fast'; in fact, they are anything but, and more geared to tiering 'down' to slower media rather than 'up' to faster media.  In addition, their large granularity (e.g. 1GB) is far too large for useful application at the consumer level.

There are other enterprise techniques, such as CADP, which are much more granular and examine 'hot areas' of HDD usage much more frequently, on the order of seconds, to shift real-time workload to SSD. While this technique is very useful for intelligent storage elements in the enterprise, at the consumer level, these techniques are too sophisticated and would result in excessive CPU usage and put strain on the I/O pathways inside consumer devices. Such devices are far better off to use file-level pinning into SSD based on OS history and knowledge.

Apple doesn't offer a MacBook with both solid-state and hard disk storage. But it does in the Mac Pro. Perhaps we will see some advances in the integration of the two types of storage in an update to Mac OS Lion or the release after.

Topics: Apple, Hardware, Storage

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  • RE: MacBook Pro and the hot new thing: Paired Storage

    sure that will make macbook pro family a far more superior computer.
    • RE: MacBook Pro and the hot new thing: Paired Storage

      @LionSaba I already use it and I am very, very pleased.
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  • Does the following example illustrate Paired Storage?

    On my iMac computer, I have a primary internal SSD boot drive with a secondary internal HDD storage unit.

    If I understood your definition of Paired Storage, this example illustrates that concept. Or am I missing something?

    But really, what is the difference if the primary internal boot disk is an SSD and any additional storage disks are external HDD units? Do both SSD and HDD units need to be internal for this to meet the definition of Paired Storage?
  • RE: MacBook Pro and the hot new thing: Paired Storage

    OWC isn't even the first... theres been kits for Macs for doing this for years... whats the news here?
  • Nothing new here

    Paired storage is common in the PC world. My buddy has been running this config in his Thinkpad for at least 18 months now. He has a 128GB SSD holding the OS and a 500GB 7200RPM drive for programs and files.

    What's annoying is that Apple ship their Macbook Pros with 5400RPM drives. It's almost like they gimp the machines to save $10.

    When the hard drive failed on my Macbook, (out of warranty of course) I went out and got a 320GB 7200RPM drive for under $80.

    The performance boost was amazing. The thing boots in under 10 seconds from cold and applications launch almost seamlessly.
    • RE: MacBook Pro and the hot new thing: Paired Storage

      @dazzlingd Apple offers 7200rpm drives as a BTO option. It was cheap enough when I bought both my MacBook Pros (in 2006 and 2010) that I opted for the option. In early 2009 (after the warranty) I upgraded the HD in my MBP/06 from 100GB to 320GB/720, which at the time cost $150. The install was easy. If I didn't still have some use for the optical drive, I would have been tempted to swap it out for an SSD. I may end up doing the optical for SSD swap on my 2010 MBP, once it comes off extended warranty and I can do with it as I choose without voiding warranty. But the 500GB 7200 RPM drive is worth every penny- the fast boot let me get working even faster than my previous MBP.
  • RE: MacBook Pro and the hot new thing: Paired Storage

    While documenting the transition from HDD technology to SSD is worth noting I'm unclear on just what's going on in the blog. As for having boot time being the primary target I'm also a big confused. I so seldom boot my MacBook that such an improvement wouldn't be noticed. OS X is so remarkably stable that I've recorded just two kernel panics in the nearly three years I've had this black beauty. I suspect both of those were caused by third party cr*pware rather than any failure of OS X.
    • RE: MacBook Pro and the hot new thing: Paired Storage

      @dheady@... I shut down my MBP whenever I am doing more than just moving around from one room to another. The last thing I want is for the HD to wake while I'm driving my car, and have a head crash. If SSDs become cheap and high-capacity enough to replace HDs for my purposes, this may change.
  • Paired storage advantages

    Well, on a MacBook Pro, or any mobile computer, it would be advantageous to have both drives internal. I bet most of us have an external drive anyway, or connection to some kind of file server like a NAS.

    But what the analysts are talking about is more than just the advantage of having boot on the faster media. In the future, we could have the two drives working together with intelligence, moving files back and forth, prefetching files based on history.

    thanks for reading,

    david m.
    • RE: MacBook Pro and the hot new thing: Paired Storage


      Correct, the idea is to move heavily used data to the faster media dynamically. So the exact location of the data at any point in timer depends on how heavily it is accessed. (or if it is part of a trend that allows some level of prediction to prefetch the data onto the faster media.)

      Data not being accessed as much would migrate back to the slower media.

      The whole point is to make the system behave as if it had a single very fast drive instead of two distinct ones. One slow and one fast.
  • The Opti-Bay has been doing this for a while

    I read about this on ZDNet quite a while back, maybe over a year.

    The opti-bay costs a bit more but comes with an external enclosure for your optical drive, so it's probably worth the uptick in price.
  • Hybrid drives

    Seagate is already selling hybrid drives with SSD for boot and HDD for storage. I am considering purchasing one for my MacBook Pro. Does anyone know a lot about this technology and if has any bugs that you are aware of?
  • RE: MacBook Pro and the hot new thing: Paired Storage

    Isn't this like the Hierarchical File System, not Apple Hierarchical File System, of yore? Hierarchical File System from IBM for the zOS (old mainframe) was supposed to store most/recently used files in highest speed access storage device (ie SSD), next most/recently used files as set up per system administrator will be stored in high speed access storage device (is hard drive) and so on until the files are stored offsite on long term storage device/media (ie tape or optical media). This appears to a variation of this idea which I think is great idea for portable systems in which Time Machine can be used as part of storage scheme.
  • RE: MacBook Pro and the hot new thing: Paired Storage

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  • RE: MacBook Pro and the hot new thing: Paired Storage

    I think MacBook Pro is one of the <a href="">best laptops</a> around and if this Paired Storage will boost MacBook Pro <a href="">house value</a>, then it would be a good thing for the users. Although Paired storage is a marriage of convenience, I do think it is a good <a href="">buying a house</a> improvement.