OWC Mercury Elite Pro Dual

Discussion in 'Mac Accessories' started by marzer, Feb 17, 2012.

  1. marzer macrumors 65816


    Nov 14, 2009
    Does anyone have experience with the OWC Mercury Elite-AL Pro Dual (Quad interface)?

    Mine is configured w/2x2TB drives in RAID1 as instructed in the manual. After running this way for a bit, I was curious how I would know if one of the drives failed. The manual indicates replacing a failed drive will be result in the mirror being automatically rebuilt but doesn't indicate how to detect a failed drive.

    After not finding anything in the manual or OWC FAQs, I contacted tech support. The rep indicated this unit had no indicator for a failed drive.

    That seems almost pointless for a RAID1. Essentially not knowing there's a problem until both drives fail? :confused:
  2. marzer thread starter macrumors 65816


    Nov 14, 2009
    The lack of response to my predicament makes me sad :(
  3. bruck macrumors newbie

    Oct 19, 2005
    online chat with OWC

    I just did an online chat with OWC asking exactly that. I was wondering how the drives in the Merc were doing and Disk Utility does not even know that its a RAID. So, I asked the question and the conversation went like this:

    With that enclosure there is, unfortunately, no warning system for a failed hard drive in RAID 1 Mirror.

    Are you saying there is no way to manually inspect the health of the drives? does't that kind of defeat the purpose of having a mirror in the first place. I can understand if it does not send out a warning, but i should be able to tell if it is no longer redundant, right?

    It is kind of pointless, which is why that model includes this note:
    "RAID 1 also supported, but we strongly recommend the NewerTech Guardian MAXimus for maximum RAID 1 performance requirements."
  4. silverjam macrumors regular

    Apr 25, 2012
    I have an OWC mercury Elite Pro with the 946 chipset so I can run two 4TB Seagate Barracudas. I agree, there needs to be a warning system. Even though I run it on a Mirrored configuration, I bought it for the options in Raid and in JBOD and separate HD's. The Newer Tech doesn't have any option but Mirrored and if your drive goes down you need to try and find an identical one.

    But with respect to your question, I see it this way.

    First of all, it is highly unlikely two drives will fail, so you don't need to know when the first one goes, you only need to be concerned if both go which is incredibly unlikely.

    Second, even though I have the Goliath of Hard drives (4 plus 4 (8TB!), it is likely I will replace them at some point in the next few years anyway, and even more likely I will run it as JBOD in a few years when Thunderbolt or something faster is fully running and I get a sexy new enclosure. I.e. it will be relegated to the garage with the old (as it will be then) Mac Mini i7 Quad Core with an insignificant 16GB Ram.

    Third, Don't look at it as two drives... look at it as one unit. How likely is it the unit will go down? I think the unit (enclosure) will fail before one of the drives, and certainly it will fail before both of the drives fail. So who cares, you still have one or two of the drives if the unit goes down. NT or OWC - both units can fail.

    I call it the 'don't worry be happy' theory to why you don't need a warning system. it is also based on the law of averages with respect to multiple failures.

    Ah who am I kidding, I am just trying to make an excuse for the fact that there is no warning system for a failed drive...

  5. radiogoober macrumors 6502a

    Jun 7, 2011

    That is absolutely *horrible* if there is no warning system. It's completely unreliable as a raid unit. Imagine if the drive in the "other" copy failed, you'd have a catastrophic, complete data loss. Ouch. RMA that crap.
  6. silverjam macrumors regular

    Apr 25, 2012
    Just a thought...

    Is anyone aware of any software that would allow you to see if the two drives in the RAID in the OWC Mercury are running? For example, disk utility software? I am not expecting any "controlling" software... i was thinking more like what you see in the Mac System Report. All one would need is details that that both drives are running and that would suggest there is no HD failure (in most cases).

    I can't imagine any Apps, but some of the new software like Drive Genius are so intelligent I was wondering if anyone knew of any?

    Personally I can't see how the software could detect two drives as the RAID is a hard drive mirror. But maybe someone knows.

    Any thoughts?
  7. marzer thread starter macrumors 65816


    Nov 14, 2009
    I opted to go with the RAID software built in to Mac OS X. Its probably not as fast as the HW raid built in the Elite unit, but at least I have fault detection.
  8. silverjam macrumors regular

    Apr 25, 2012
    Interesting post on another site I have quoted/linked below. If this is true its a very fundamental aspect of the enclosure that they failed to mention!!

    I have emailed OWC to confirm.


    "Last update: OWC tech support just called me back. He says (on the enclosure I bought) if one of the two drives goes bad, the flickering blue LED will turn red. Looks like a good deal at $69.."

    See: http://www.sportsshooter.com/message_display.html?tid=39977
  9. silverjam macrumors regular

    Apr 25, 2012
    Final Clarification from OWC

    I received an email from OWC today stating the following in relation to my query:

    "the LED will be red if a HD has failed. Always keep your 'good' HD on the main SATA connector inside and the secondary above it. If you replace the main it will erase the secondary as well".

    I have no idea why they don't state this to avoid any confusion? Perhaps they don't want to visit the issue of a failed drive from a marketing point of view.

    Also it would be interesting to hear from anyone who gets a failed drive, or has a failed drive to test to confirm the "Red LED" alert.

    Note also the further comments from OWC relating to my question of what is the configuration if there is a failed drive. This is fairly important as well. The RAID Mirror is rebuilt from the Primary Drive (plugged into the circuit board). So if the Primary drive fails you will need to swap them over before inserting the new drive. Having said that, if I get failed drive I will probably back-up to another disk (which I sort of do anyway) and rebuild the Raid entirely.

    So now we can all sleep at night.

  10. normd1954 macrumors newbie

    Nov 1, 2007
    So how do you know which drive failed - the primary or the secondary?

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