Previous 1 2 Next 15 Replies Latest reply: Sep 24, 2014 5:54 AM by Ernst Mulder
tuckshoprn Level 1 Level 1

My mac mini is set up with two sata disks installed, one is a 128 ssd and the other a 1tb hdd.  Since installing mountain lion, the hdd keeps ejecting itself, and i get a message saying - this hard disk was not properly ejected. then i wont find the disk in finder, or disk utility!.  I then have to remove the hdd from the mac mini and plug it into a usb caddy, which finds it no problem, and then when i put it back in the mac mini, it works again!! so the disk is not faulty i dont think.  It then works for a period as random as a few hours, to a few weeks and then i will randomly get the "this disk was not ejected properly" message and it has again dissapeared.  I use the mac mini as a media centre and it isnt really being pushed hard when the failure happens.


Anyone have any ideas as to whats wrong?

Mac mini, OS X Mountain Lion (10.8.2), 128GB SSD, 1TB HDD, 4GB Ram
  • BDAqua Level 10 Level 10

    Hello, what brand model is it?


    Open console in Applications>Utilities, check the system log for the date/time of the last problem for clues.

  • tuckshoprn Level 1 Level 1

    Hello, Sorry for the late reply.


    When i open console after the ejection i get the message:


    01/11/2012 22:32:42.000 kernel[0]: Failed to issue COM RESET successfully after 3 attempts. Failing...

    01/11/2012 22:32:42.000 kernel[0]: disk1s2: no such device.


    Hope this gives a clue, i'm tearing my hair out over it.  there is absolutely nothing wrong with the disk itself.

    If i do a full shutdown and restart, it finds the disk again no problems, but if i simply choose to restart from the menu, it does not find the disk again.


    Thanks for any help you can give on this.  I have only been experiencing this issue since i upgraded to mountain lion.


    Drive information:



      Capacity:          1 TB (1,000,204,886,016 bytes)

      Model:          SAMSUNG HN-M101MBB                     

      Revision:          2AR10001

      Serial Number:          S2R8J90B815515     

      Native Command Queuing:          Yes

      Queue Depth:          32

      Removable Media:          No

      Detachable Drive:          No

      BSD Name:          disk1

      Rotational Rate:          5400

      Medium Type:          Rotational

      Bay Name:          Lower

      Partition Map Type:          GPT (GUID Partition Table)

      S.M.A.R.T. status:          Verified



      Capacity:          209.7 MB (209,715,200 bytes)

      BSD Name:          disk1s1

      Content:          EFI

    living room:

      Capacity:          999.86 GB (999,860,912,128 bytes)

      Available:          648.66 GB (648,662,093,824 bytes)

      Writable:          Yes

      File System:          Journaled HFS+

      BSD Name:          disk1s2

      Mount Point:          /Volumes/living room

      Content:          Apple_HFS

      Volume UUID:          D6125397-BAE7-3496-9B9C-6534EEE0B660

  • BDAqua Level 10 Level 10

    Bootup holding CMD+r, or the Option/alt key to boot from the Restore partition & use Disk Utility from there to Repair the Disk, then Repair Permissions.


    If that doesn't help Reinstall the OS.

  • RRFS Level 5 Level 5

    I would also do a SMC reset



  • cooa99 Level 1 Level 1

    Hi all,


    I am having this same exact issue on my mac mini server (2011) on its 2nd HDD.


    I have the same SAMSUNG HN-M101MBB as the OP.


    any clues please?

  • tuckshoprn Level 1 Level 1

    I got it fixed in the end, but I had to reformat the disk. Repairing disk and permissions didn't seem to help, nor did the SMC reset. But it's good as gold now. Hope this helps.

  • cooa99 Level 1 Level 1

    thanks for the reply,


    I'll give that a go as well

  • cooa99 Level 1 Level 1

    ok, i have reformated the drive and same thing is still happpening.


    any more clues?. its such a pain taking the 2nd hdd drive out

  • tuckshoprn Level 1 Level 1

    Not sure what else you could try. Formatting the drive did it for me. You could try swapping the drive into the other bay, in case that makes a difference, although I'm not sure why it would. Did you use the mac os x extended journaled option when formatting, using a GuiD setup? I also found that after it had ejected, I didn't have to remove the drive, just power off, and then restart. However just selecting restart from the OS X menu would not bring the disk back, it had to be a cold boot from power off for it to see the disk again.

    If you have the patience you could reinstall OS X from scratch after having formatted both disks, just so as to be sure nothing spurious has been left in the system. Otherwise the only other thing I can suggest is a trip to the Genius Bar, although I'm not sure what help they'll be in this situation.


    Hope you find a solution soon. I may have just struck it lucky, as all I did was reformat the drive.

  • sdjordan Level 1 Level 1

    I've just started getting the same problem on my Macmini server, before I start reformating, did anyone come to any further conclusions or other things to try?

  • tuckshoprn Level 1 Level 1

    I found that the reason it was happening to me was that the mac was still seeing the drive as an optical drive and because I had the power save options set to turn off discs when not in use, it kept turning it off in a way such that the OS thought it was ejecting. I just set the power save feature to never turn disks off. Which isn't really the solution I was after but it worked.

  • awirealvr Level 1 Level 1

    setting power save option to not turn disks off did it for me too



  • cooa99 Level 1 Level 1

    lol, only just seeing the comments.


    thanks guys for finding the problem and solution.


    I ended up replacing the internal drive (and upgraded to mavericks) a while back but still kept hold of the drive with the issue.


    I ran a few tests on it and could not find any issues.  Good thing I did not throw it away!


    So looks like I can now go back to using the drive ... in an external enclosure

  • awirealvr Level 1 Level 1

    I had the ejecting problem with my SSD in both an optical drive bay and an external fire wire enclosure.


    Setting the power save option to "never turn disks of" keeps my SSD on the desktop.

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