Raid 5 on the 2010 Mac Pro

Discussion in 'Mac Pro' started by Fesan, Oct 4, 2011.

  1. Fesan, Oct 4, 2011
    Last edited: Oct 4, 2011

    Fesan macrumors member

    Feb 19, 2010
    So, I bought four 2tb Caviar blacks wanting to raid 5 it up. Then after installing the discs I see that the only options for software raid in OS X are zero, one and JBOD.

    I have searched the net for a few hours trying to find a solution other than forking out the cash for a apple raid controller without luck.

    I'd be willing to spend alittle on a card to manage the raid but not willing to spend alot over 100$.

    Does the braintrust on here have any suggestions to how I can get my raid 5? Are there any ways to do it with software or any cheap raidcontrollers out there?

    I know I could do a one+zero but 50% capacity loss is alittle more than I am willing to take. I'd rather just go raid zero if those are the only options:)

    PS: Is it possible to bootcamp on software/hardware raid?
  2. milbournosphere macrumors 6502a


    Mar 3, 2009
    San Diego, CA
    I don't know much about the alternatives for the Raid 5 array, but I will tell you my experience with Bootcamp and RAID.

    In a word, it isn't pretty. I have two software RAID 0's in my tower and an SSD to boot from; I actually had to remove the drives to successfully install Windows 7 via Bootcamp on the SSD. Once I did get the OS installed, I had to disable the HFS drivers that Apple's driver disk installs just to stop getting bluescreens. I tried many solutions, but I ended up having to delete the driver and use VMWare to move any data between OS X and Windows. It's dirty, it works, but it really is a bad solution. If you use Windows in Bootcamp for anything other than gaming and need access to your data, I wouldn't recommend using your drives in a Raid array. If you could use Windows in a VM, you'd be just fine.

    Perhaps the newest HFS drivers do better, but when I tried again around six months ago, I still had issues.

    TL;DR version: If you need Windows and you need to get it data off of your HFS RAID array, you're probably better off just using a VM.
  3. Pressure macrumors 68040


    May 30, 2006
    MacZFS will enable you to use the much superior ZFS+ filesystem, so you can use RAID-Z1.

    It will require some reading and research on your part but it is free and you will have access to 6TB.
  4. nanofrog macrumors G4

    May 6, 2008
    The only cards for ~$100, are software based (uses system resources to process the RAID functions), which you don't want to use for RAID 5 due to their lack of NVRAM to deal with the write hole issue associated with parity based arrays (need a hardware RAID controller for this). What all of this this means, is you'd end up with corrupted data at some point. :eek: :(

    Unfortunately, a hardware RAID controller that can do RAID 5 will set you back at least $300 (4 port). Compared to corrupted data however, it's worth the additional cost if you must have RAID 5 (or 6/50/60/51/61 if the card supports it).

    But there's a down side to such controllers, which is you need to use enterprise grade disks (due to the different recovery timings programmed into the drive's firmware). Which means the Caviar Blacks you've bought won't work properly (unstable, if you even get it to initialize).

    Don't do it (see above).

    Unfortunately, NO.
  5. Fesan thread starter macrumors member

    Feb 19, 2010
    Thanks for the tips guys:) Think I am going to striperaid three of the discs and use the last one as Bootcamp/backup disc.

    This way I'll get speed on most of the discs and be able to back up the most important documents, apps etc on the fourth whilst hopefully running Bootcamp on it without much trouble as I rarely move data between the OS discs and the bootcamp one:)

    Will definately read up on MacZFS to check out what it is!
  6. nanofrog macrumors G4

    May 6, 2008
    ZFS Wiki (to see what the ZFS file system is).

    Then you might want to look up RAID-Z, as it's very similar to RAID 5 (but doesn't suffer the write hole issue), and can be done with an inexpensive drive controller (ICHx on the logic board, or 3rd party card = inexpensive hardware if you need any additional hardware at all). Consumer disks are also usable, which further reduces costs.

    I didn't know about MacZFS prior to this, which is why I didn't mention ZFS (possible via a VM, but would be more complicated).

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