So I Bought A RAID 1 Hard Drive...

Discussion in 'Mac Accessories' started by Mac In School, Aug 13, 2008.

  1. Mac In School macrumors 65816

    Joined:
    Jun 21, 2007
    #1
    I bought a Lacie 2big Triple, and have successfully configured it to use RAID 1 (mirrored).

    There are two blue lights on the back. They flash on both sides, and that means both sides are working. Are those blue lights my only indicators when a drive goes out? Sure would be nice if there is some kind of desktop notification. Anyone know how this works?

    Thanks.
     
  2. dimonay macrumors member

    Joined:
    Jan 16, 2008
    #2
    I haven't seen any utilities for OS X that monitor any RAID setup, so those lights are probably going to be the only way to find out if a drive dies.

    If it was RAID 0 it'd be simple, the notification you'd get would be that the disk wouldn't mount :D
     
  3. blodwyn macrumors 65816

    Joined:
    Jul 28, 2004
    Location:
    Portland, Oregon
    #3
    There's an application that does this, but it's expensive IMHO - Raid Alert. Alternatively the terminal command "diskutil listRAID" (without the quotes) will give you a status report. Obviously this only works if OS X knows it's a RAID setup, and not the drive doing it within it's own firmware.

    If you wanted, you could compile this AppleScript to turn it into an application:

    set RAIDstatus to do shell script "diskutil listRAID"
    display dialog RAIDstatus
     
  4. Mac In School thread starter macrumors 65816

    Joined:
    Jun 21, 2007
    #4
    Ahhhhhh... Yes. So if it's a hardware RAID, handled within the drive, I'm screwed, huh? I wondered why Disk Utility didn't show two disks. I guess I store the drive with the back facing me, and glance over every few week.
     
  5. blodwyn macrumors 65816

    Joined:
    Jul 28, 2004
    Location:
    Portland, Oregon
    #5
    If disk utility only shows one volume, then I think you're out of luck. Your only other option is to set up the drive as a JBOD, and then use Disk Utility to build the RAID mirror. Then you could use the utilities to monitor it.
     
  6. Thiol macrumors 6502a

    Thiol

    Joined:
    Jan 26, 2008
    #6
    Wouldn't that defeat the advantage of hardware RAID?
     
  7. blodwyn macrumors 65816

    Joined:
    Jul 28, 2004
    Location:
    Portland, Oregon
    #7
    Yes, but there's really no such thing as hardware RAID, you're just making a choice as to whether you want the firmware in the drive electronics to manage the RAID, or use OS X.

    There may be a moderate performance advantage in using the Lacie to do it, as it will cut down on the data traffic on the USB or Firewire bus if the mirroring is handled within the enclosure. Using OS X to manage the RAID means you can monitor it, and in the event of one drive in the mirror failing, which do you fancy your chances with best in helping switch the drive out and resilvering the mirror? (assume you can swap one of the drives in the enclosure and not have to return the whole thing).

    You roll the dice and place your bets: Do you entrust your mirror to OS X or the Lacie firmware?
     
  8. Mac In School thread starter macrumors 65816

    Joined:
    Jun 21, 2007
    #8
    Speed isn't a huge issue. I'm just using it to stream DVD rips to my AppleTV. I'm guessing the network speed itself is slower than whatever slowdown I'd experience from doing this.

    Do I lose my hot-swapability by having OS X control the RAID?
     
  9. blodwyn macrumors 65816

    Joined:
    Jul 28, 2004
    Location:
    Portland, Oregon
    #9
    If one disk fails you can add another to the mirror, and OS X will rebuild it, although it can take upwards of 20 hours to rebuild a mirror of ~300GB (using USB). You can mount and unmount the mirror to move the drive around without rebuilding though.
     

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