I need help with the correct sequence to set up RAID arrays...

Discussion in 'Mac Pro' started by Michael Russell, Jul 19, 2010.

  1. Michael Russell macrumors newbie

    Apr 25, 2010
    Yesterday I bought a new Mac Pro. I absolutely LOVE it, and don't care if they replace it tomorrow. It is a terrific machine. I do want to set up two sepeate RAID arrays inside it, and could use a little help, as I've never done this before.

    I want to set up one array, of two large (say 1TB) drives in mirrored (RAID 1?) format for all my data. I want to set up another of two smaller (300GB) WD Velociraptor drives, which I already own, in striped (RAID 0?) format for the operating system, and my applications, as well as a bootcamp partition.

    This is where it gets complicated for me. Much of my data is on one of the velociraptor drives in another computer. My question is, can I install the two new 1TB drives, set them up as RAID 1, using the original drive that came in the Mac Pro, move my data over from the old computer, then install the velociraptors, set up that RAID 0 array, and install the operating system. In other words, will the "new" operating system recognize the data raid array that I had created with the "old" operating system?

    An easier question. When setting up the operating system on what will be my new RAID 0 array, do I just boot from the CD? and secondly, do I first set up the striped raid, and then install the operating system, and then the bootcamp partition? Or is there a different sequence to use.

    OK finally, when booting into windows through bootcamp, will windows be able to see the seperate data RAID array?

    Thank you for your help, as you can tell I need it!

  2. nanofrog macrumors G4

    May 6, 2008
    This is doable in terms of what you have, and can be accomplished in the MP without the need to spend a single cent of additional funds. :)

    BTW, you were correct in your terminology.
    RAID 0 = Stripe Set
    RAID 1 = Mirror

    What I don't see, is mention of a backup system. You must understand that a Mirror, (nor any other RAID level) is NOT a substitution for a Backup. The reason is, if you make a mistake, it gets duplicated on the mirrored disk automatically. So recovering from that mistake can only occur if the data is stored on an independent source. It's situations like this or worse (when it really hits the fan), that you find yourself needing a backup system in place.

    Off-site is there for the natural disaster aspects, such as fire or flood, that an on-site alone won't solve.

    Yes, as the array's setup information is stored between the MBR and GPT (GUID Partition Scheme) the disks are formatted with (stored on the drives, not a ROM or within the OS).

    I can't say from actually attempting this however, as I use true hardware RAID cards for my arrays.

    Yes, as you would have dumped the original OS installation that came on the OEM disk (since it will be used to transfer data from the original system to the new one). Otherwise, you could just clone it (OEM disk = source, stripe set = destination).

    Yes. The array has to be created first, as the initialization process will wipe any existing data the drives may already contain. No way around this.

    Unfortunately, you're not going to be able to do this OTB (Out of the Box).

    When you create an array under Disk Utility, it modifys the firmware where the SATA controller on the logic board won't even be able to boot a Windows disk (if it did, you'd still need to have Windows on a separate disk, as the GPT system OS X uses is incompatible with Windows).

    Get a PCIe SATA controller (internal port BIOS based card is needed to boot Windows off of the HDD). A card based on the Silicon Image 3132 chip will work (example), and it's cheap (SATA 3.0Gb/s spec). Then attach a separate disk to the card with a standard SATA data cable. Physically locate this disk in the empty optical bay, and use the following to get power:
    Backplane Extension Cable
    SATA Power cable

    Remove the Molex end, and splice the power lines together (follow the wire colors and locations - easy to do). You can do this with solder and shrink wrap, crimp connectors, or small wire nuts. Really easy, and it won't void the warranty, and allow you to use another disk on the SATA controller on the logic board if you need to.

    There has been some mention of a hack to get around this issue as well, but it's very complicated (not convinced that success is all that high as a result, and it may not apply to every Intel based MP). For the money (inexpensive solution beyond the cost of a drive, if that's necessary), it's worth it IMO to go with the method described above.
  3. Michael Russell thread starter macrumors newbie

    Apr 25, 2010
    Thank you very much for the detailed reply, I really appreciate it.

    I think perhaps I will skip the raid ) array for the operating system, as the bootcamp issue looks rather complicated, and instead perhaps just install a SSD as an alternative solution for quick app and boot speed.

  4. nanofrog macrumors G4

    May 6, 2008
    Easy enough to do, and you can also run a separate disk this way as well, and attach it to the logic board.

    BTW, BootCamp is just a partition tool, and why you don't need to run it on a separate disk used as a Windows installation. You would need to run the setup.exe file though, as that installs the drivers (particularly on older versions of Windows, as they won't automatically locate the drivers if they're available from MS).

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