How to Resolve a “Partition Failed” Error in Mac OS X
If you have attempted to partition a drive from Mac OS X and received a “Partition failed” message with the error “Couldn’t modify partition map because file system verification failed.” you can fix the problem with the file system check command line utility. To do this properly, you’ll need to boot into Single User Mode as well:
- Reboot the Mac into Single User Mode by holding Command+S during boot
- At the command prompt, type:
- When fsck is complete, type “exit” or “reboot” to reboot
- Boot the Mac as usual, verify the disk again in Disk Utility, and partition as usual
/sbin/fsck -fy
Boot the Mac as usual and relaunch Disk Utility to verify the disk. Go ahead and partition the drive as usual, this time without any such error message.
I have encountered this error a few times when partitioning the boot drive from OS X Lion, most recently after a clean installation when setting up dual boot for OS X Lion and Mountain Lion. The cause of this remains to be seen, and repairing the disk from Disk Utility itself doesn’t work, even when in Single User Mode or when booting from another drive.
Thanks for posting this… I had this exact error last week!
Thanks a lot. I was looking for something to fix that since ever !
Before you bail into the command line… this error will occur depending on the sequence of your clicks and drags on the partition map. It seems to be, at least partially, a calculation error, programming parlance is “fence post.” The fsck (filesystem consistency check) utility should be used with some caution however. Please see http://support.apple.com/kb/TS1417?viewlocale=en_US&locale=en_US
-b
I had this same issue and fsck did not fix it for me. I ended up using super duper copy to make a backup image on a USB drive then booted from the backup drive and used super duper copy format the drive and copy the files back to my main hard drive. It worked great and I was able to make a 200gig windows 7 partition on my early 2009 iMac.
[...] Via | OSXDaily [...]
worked great – looking for this for a long time !
txs!!
Spot on. Worked like a charm. many thanks!
Thank you! I tried removing a Boot Camp partition on my File Vault encrypted drive and encountered this issue. Switching off File Vault didn’t resolve it but following these instructions did.
thank you man!!!! honestly, thank you so much. u have no idea how grateful i am!!!
Thanks thanks. This saves me from hours trying to get a partition to install windows on my mac.
Thank you! After searching all over the place, this finally did the trick. My Boot Camp partition succeeded immediately.
Help!!! I was trying to do a BootCamp so i can install windows 7. I found this as a solution to my problema, but after i did this, my hard drive is full and i just have 10 gb of free space, it says:
Audio: x.x GB
Movies: x.x GB (THE X’s are just examples, not real GB’s)
.
.
Other: 320.5 GB !!!! WTFFF, PLEASE HELP ME HOW CAN I FIX THAT
This is due to a miscalculation. THis tutorial should solve it.
Thank you for posting this online it has saved me alot of time and prevents from reformatting disk and starting from scratch. You are a legend.
Just I want to say thank you, really I spent two days to find any solution to this problem. Worked great
really worked for me. Many thanks
Worked like a champ! Thanks!
I tried the fsck and it couldn’t be repaired after 3 attempts. What now?
yes, it worked right away. i’m new to mac so i wanted to do dual boot with windows and made my partitions with disk utility, when i tried boot camp it told me the disk should be one partition only…the problem arised when i deleted my previous partitions and trying to enlarge the main partition to full size.
thank’s man it’s really worked, removing boot camp partition
juste force quitting itunes
Thanks for the tip! Got this error when trying to resize Bootcamp partition during the Winclone process. Your solution worked for me.
Saved my day. Thanks!
Fantastic! Worked perfectly!
Thank you so much this help me a lot!!!
Many thanks. Much appreciated.
Hello,
I have a problem with this.
I have a ssd as my main drive for running mac and have a hdd instead of my superdrive. But I want to keep part of this secondary drive cause it has my photo/music/… library on it.
Is there a similar command that could fix this for the secondary hard drive? Just as easy as this so I don’t need to replace all files (250+gb) to an external and back?
Please send me a mail or something, would be much appreciated !!!
thanks that was big help for our Community
Thanks but just the restart worked for me
I had the same problem: could not create a partition. Followed these instructions and voilá, it worked right afer that.
Finally fixed my problem partitioning. I took a screen shot of the process too. It was missing some blocks on the HDD:
** Checking volume information.
Invalid volume free block count
(It should be 63457968 instead of 47085599)
After that, it repaired it and checked it again. Then the employee (I work in IT) explained that he was missing 150-200GB’s of free space on his HDD. That showed up also. Finally able to partition after this. Tried many other ways of fixing it. He can finally dual boot to Windows 7 and Mountain Lion. Thanks!
hi
for me the error msg is not this…instead –
“The disk cannot be partitioned because some files cannot be moved.”
so if its the same as the above then shall i do this process or what should i do…i have macbook pro with mountain lion 10.8.2
thx
ash
oops! sorry for the double post didnt realize i had already posted…my bad…
Excellent article!!
While removing windows 7 boot camp partition via BCA tool on OS X Mountain Lion, it complained “failed to remove”.
However after rebooting MacBook Air noticed that Boot Camp was gone but was not able to merge the partition using Disk Utility. It gave the same message as in this article. Followed the steps in this article and after rebooting everything works perfectly.
Happy to recover the unused 50GB of Win7 on my 128GB MacBook Air.
Thank you so much!!
Thanks. I love it when what I read online actually works.
I typed /sbin/fsck -fy exactly and it says it is not recognized. Not sure what I am doing wrong.
I had same problem. Type; sbin/fsck -fy. I removed the 1st (/)it worked for me.
This fixed a problem I had trying to recreate a bootcamp partition. Thanks!
THANK YOU!
sweeeeeeeeeeeeet worked like a charm….
Thank you very much !! it fixed my problem and i installed windows normally
thanks a lot !!! very good fix !!
If you have rEFIt installed, the startup commands (Cmd+S) won’t work. But this is simpler to do in rEFIt: just hold Option for the menu to come up, then hit F2 and select ‘Boot into single user mode’. Then run the command mentioned above and voila!
Hey man, you saved 20GB from my 128GB SSD. Thanks a lot!
Hi, I tried this and now Mac OS X 10.8 won’t boot. The grey Apple loading screen now has a loading bar on it, and when it gets to the end, the Mac shuts down.
Help anyone?
Hi,
i had the same error,
just try the suggestion but still same error msg still occured.
need help.. thanks
Thanks a lot! this worked like a charm!