expand raid-0 and convert to raid-5 ?

Discussion in 'Mac Accessories' started by kvdv, Nov 30, 2009.

  1. kvdv macrumors member

    Joined:
    Apr 5, 2008
    #1
    Hi,

    I have a failed WD My Book Pro II and I'm looking to replace this enclosure with the Mercury Elite-AL Pro QX2 4-bay Hardware RAID enclosure.

    If I move my two SATA drives (currently configured as a Raid-0) from the My Book to the QX2, will I be able to access my data?
    And would it be possible to expand this existing Raid-0 when I insert a third drive?
    And will I be able to convert the raid-0 to raid-5 as well?

    Thanks,
    Kris
     
  2. KnightWRX macrumors Pentium

    KnightWRX

    Joined:
    Jan 28, 2009
    Location:
    Quebec, Canada
    #2
    Are you sure the failure is the enclosure and not one of the drives ? Also, if it's hardware raid, losing the controller usually means you need to get an identical one in order to get back your data. If it's somekind of software raid, just using the same software will get your data back.

    However, if one of the drives died, forget about your data. One of the drawbacks of RAID-0 unfortunately.
     
  3. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #3
    No.

    1. If the current array failed, it's gone. Assuming it's a bad drive, you have to isolate and replace it. So you need to determine exactly what happened. Try running SMART and a scan for bad blocks, and see what happens. BTW, if there's been any tell-tale noises (i.e. clicks), it's likely a dead drive.

    2. It's software RAID (drivers), not a proper hardware controller, and can't be transferred. To switch it, the initialization will wipe out any existing data.

    Either way, the data's gone :(, so I hope you've a backup. And even with RAID, you must have a backup. There's no way arround it, assuming you want to keep your data. ;) :p
     
  4. KnightWRX macrumors Pentium

    KnightWRX

    Joined:
    Jan 28, 2009
    Location:
    Quebec, Canada
    #4
    Only if it uses some kind of proprietary software RAID (and if you do, you deserve what you get). Any sensible software RAID solutions can rescan devices with no problems to give you back your data once the drives are presented on another controller (things like Disksuite, Linux MD, LVM...)

    Especially with RAID-0. Each drive you add to a RAID-0 makes it more suceptible to massive failure.
     
  5. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #5
    There's enough of it out there, and it's not easy to spot.

    The Mercury Elite-AL Pro QX2 gives me the impression of a proprietary device from what I can tell. It claims the ability to rebuild, even if not connected to a computer, so it's got a small main board. It's still software RAID though, not a proper hardware controller. Not for $329.99 empty.

    Also, it uses an Oxford chipset, which are problematic. I avoid those like the proverbial plague.

    It's not gone well in my experience with things like this, and I take the approach of test it out to see what it can do. But you can (and usually do), eat a restocking fee and shipping if you have problems with it.
     
  6. FireWire2 macrumors 6502

    FireWire2

    Joined:
    Oct 12, 2008
    #6
    expand raid-0 and convert to raid-5 ?

    The answer is no - Once the RAID o broke, that is it data is gone!.

    I assume you have raid0 due the speed, then get this eBOX-R5 - eSATA raid5 hardware raid box can transfer about 230MB ~ 250MBsec, and email notification.

    Remember protected raid like raid1, 3, 5 and 6 are hardware failed proof, not software, and corrupt files

    Hope this help!
     
  7. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #7
    I'd need to see more on that unit though, as the language on what I found wasn't clear to me.

    I've more of an impression it's an Atom processor + board (or similar) running software RAID. Any form of software RAID is NOT suitable for parity based arrays (5/6/50/60), as they can't handle the write hole issue. Such solutions are common in a "box" that does it all (RAID methodology built into the enclosure). Those I've seen that really do have a real RAID card, are actually separate (must be installed in the system), and are far more expensive. Then there's selecting the parts separately.
     

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