I've been noticing some oddities with my computer lately. Applications running slower than normal. Hanging. I decide to run Disk Utility and I get the following statement:

Volume bitmap needs minor repair for orphaned blocks. Invalid volume free block count. The volume was found corrupt and needs to be repaired.

So I do what it says and restart my computer. Once it restarts, I hold CMD + R until the Apple logo appears. Once the OS X Utilities window comes up, I select Disk Utility. I proceed to select my Mac HD, run Verify Disk and then Repair Disk. Both say they're "Ok." I restart as normal. That should seem to fix the problem, but I am still getting the following message every time I run Disk Utility.

How do I fix this issue? Any help would be appreciated.

My MacBook Pro specs:

  • OS X 10.9.1
  • 2.7 Ghz Intel Core i7
  • 16GB 1600MHz DDR3 RAM
  • 750GB SSD
  • Do you have FileVault running?
    – user10355
    Feb 5, 2014 at 0:07
  • I do have FileVault running.
    – Hynes
    Feb 5, 2014 at 0:07
  • 3
    This pertains to you: alanhan.net/… As an aside, while some may claim these kinds of errors are minor, issues with file systems tend to signal hardware faults. I would run smart analysis (don't just rely on a PASS or FAIL) and even consult more detailed hard drive integrity software, such as Disk Warrior to scan for faults. I tend to take these errors seriously based on my experience and history of failed drives.
    – user10355
    Feb 5, 2014 at 0:27
  • @cksum That fixed the problem. If you post your comment as an answer, I'll mark it as accepted.
    – Hynes
    Feb 6, 2014 at 14:19
  • Glad it worked out for you. Answer added below.
    – user10355
    Feb 6, 2014 at 21:54

3 Answers 3


The apparent issues seems related to FileVault. The following steps seem to be the cure:

  1. Go to “System Preferences” – “Security and Privacy”, click on “FileVault” tab, click the lock icon on the bottom left to unlock, then click on “Turn Off FileVault”. The decryption process will take a while (hours).

  2. When the decryption is done, reboot into Recovery HD.

  3. Use Disk Utility to verify OS X Partition, this time the process will take much longer and it will give you the same error message.

  4. Click on “Repair Disk”.

  5. DONE!

  6. (Optional) Re-enable FileVault.

Source: http://alanhan.net/how-to-fix-volume-bitmap-needs-minor-repair-for-orphaned-blocks-on-os-x-10-8/


I have successfully used Diswarrior hundreds of times over the years (starting with Classic O/S) and I can't remember when it didn't fix file system issues.

Unfortunately Disk utility is a pretty basic disk repair utility and does a great job for what it is but for really serious issues like this. DW may be your only choice.

I would contact Alsoft about your issue, probably just link back to this thread so they can see the exact error.

I have never used DW on a volume with FileVault and am not sure of it's efficacy so check with them first, unless someone here can tell me I either am or am not full of little red ants...


The filesystem on your OS X disk has developed some errors. You've checked the filesystem using disk utility, but you cannot repair a running disk, as the greyed out button indicates. You've rebooted into recovery mode (booting from the recovery partition with Cmd-R, leaving your main OS partition unmounted) so you can repair your corrupted filesystem now. However, because your filesystem is encrypted using FileVault, it appears to the disk utility in recovery mode as a single file--a large encrypted disk image. Checking the volume appears impossibly fast, and it always returns zero (0), indicating a clean filesystem check. If you want to check the filesystem inside the encrypted disk image, you first need to unlock it from the disk utility file menu. After typing a password to unlock the image, you can check it normally. It will take a longer time, but a lot less time than turning FileVault off and back on again.

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