7 Replies Latest reply: Dec 3, 2012 3:01 AM by mctoom
mctoom Level 1 (5 points)



I've made a lot of research about this problem before I post this. I found a lot of posts having a similar issue, but all the posts didn't have a resolving answer. I'm hoping that this one will.


I have a mac pro (10.8.2) with 3 SATA drives in it. All drives are the same type, all came originally with the mac. Today, I turned on the computer, and the first thing I got is a message saying "The disk you inserted was not readable by this computer" with three options saying "initialize", "ignore" and "eject." I clicked "initialize" and it opened the Disk Utility for me and I noticed different things:


The first thing I noticed is a drive named "Media" on top of the list. It doesn't have any information. Total Capacity is 0. Its Connection ID is Bay 3 (The dead drive apparently). I don't know why it is named Media. It cannot be erased, verified nor repaired. All options are grayed out.


The second thing I noticed is that the 3rd drive is missing from the list. It used to have the name Macintosh HD 3, but now it's not there.


I opened the Finder to check things out. Macintosh HD 3 is not there. Even this drive Media is not visible also.


I rebooted the Mac using the recovery mode. I went to the Disk Utility. Same thing. Media is on top. Disk 3 is missing.


What happened before that? Last night. I tried to create an encrypted blank disk image inside Macintosh HD 3, but the process was stopped for some reason. I don't remember what was the error message exactly. The image file was there on the drive although the process stopped. I couldn't delete it. I suspect that this could be related to the disk failure somehow. Is it dead?

  • Linc Davis Level 10 (192,431 points)

    Try to partition it. If that fails, move it to another bay, or to an external enclosure, and try again. If that fails, then yes, it's dead.

  • mctoom Level 1 (5 points)

    I can't partition it because it says "The disk is too small to contain partitions."


    I moved it to another bay, same problem.


    I guess it is dead then. You know what could be the reason? Knowing that could make me feel better at least.

  • Grant Bennet-Alder Level 9 (56,585 points)

    Rotating drives are really quite complex. They contain a micro-controller, a little private RAM, a buffer at least as big as a Track, and a Sea of Magnetic media. All that stuff has to be working correctly for the drive to be useable.


    Data are written to the drive using a semi-redundant code that can accommodate bursts of errors. Each read is passed through error-correction logic in an attempt to launder out any bursts of errors that may have occurred.


    The Sea of magnetic media is so vast that there will inevitably be defects in the magnetic regions. Drives have always had the ability to have a few spare blocks, and the micro-controller can make semi-permanent substitutions for any blocks found to be bad at the factory. There are also spare blocks that can be substituted for blocks that go bad in the field (they may or may not be from the same pool of spares as the factory spares.)


    In some drives, important drive information, such as the spares substitution table, is stored on a private track on the drive. If that information becomes unusable, the drive cannot report a sensible size/capacity.  At that point, the drive is unusable.


    There is also certain analog calibration and track location information encoded on the drive. If that gets messed up, the drive is unusable.


    It can also develop so many Bad Blocks that there are not enough spares to fix it up. At that point it may continue to respond to requests to initialize, but initialization will fail. Then the drive is not reliable enough for you to trust it with your data, and should be retired.


    And lastly, some drives encountering internal errors will simply "disappear". They drop out and no longer show in System Profiler when they encounter a serious internal error. Only a power-off cycle brings them back for a little while, then they drop out again.




    I think what you are fishing for is, ¿Did I do something wrong to make this drive die?


    The answer is, you did not. Stuff happens. Drives die.


    "Any drive can fail at any time." That's why we need backups.

  • The hatter Level 9 (60,930 points)

    Sometimes you just need to remove all partition tables.


    A bad sector residing in hidden tables can render the entire drive useless.


    Initialize the drive fully, no partitioning, and while Disk Utility can zero all the drive that is not 100% method. But anytime you repartition erase to one partition, it does check the partition table areas for bad sectors because those cannot be mapped out later.


    I would never buy drive from Apple. And if you have Seagate or WD, then using their Windows tool (their boot CD won't work on a Mac to see the drives) is one good way, using Lifeguard or Seatools for instance. Or look for another Mac friendly method.

  • mctoom Level 1 (5 points)

    I can't thank you enough for this enlightening response. I really appreciate it.

  • mctoom Level 1 (5 points)

    Thanks a lot The hatter, that was really helpful.

  • mctoom Level 1 (5 points)



    My external drive (External 2TB WD) just died with the same symptoms exactly today. Can this be really a coincidence to have two drives failing within a week? I'm having the feeling now that there is a cause for this, whether external (like electricity) or internal (a virus).