MacOS – How to resolve error: “Couldn’t modify partition map because file system verification failed”

disk-utilitymacospartition

I upgraded to Lion and decided I no longer want 100 GB of my drive devoted to Boot Camp, I never boot into Windows, I just use it as a VM anyways. So I deleted the boot camp partition using disk utility and then attempted to expand the main partition to fill this now unallocated space. I also deleted the boot camp from inside VMWare Fusion. When I go to expand it, I get the error in the title of this question.

After searching this forum and Google, I found a lot of people with similar problems but none receiving this exact error with any resolution. I do not want to do a clean install if at all possible. I have enabled debug mode in Disk Utility and tried other stuff, but to no avail.

I've tried editing it in normal and in debug mode while running Lion, and I've tried in recovery mode.

Here are screenshots of the error and whatnot. Any ideas?

Error message received

diskutil list output

UPDATE: I verified my disk and got these errors. Attempting to repair but worried that my Snow Leopard disk will overwrite the Lion recovery partition….

Drive errors

Best Answer

OK, this isn't too bad. Reboot while holding Command ⌘-S to enter single user mode. When it gives you a prompt, type

fsck -fy

then press return. it will repair your disk. When it's done, type

reboot

and try partitioning again.

Related Solutions

MacOS – How to resize the Lion partition to fill up the unused space on the drive

My suggestion

Don't try to resize from the Recovery partition. Boot into the normal partition and resize from there.

Background

diskutil list is misleading you. It is not the position of the recovery partition which is your problem.

I had a very similar setup, and here is the output of diskutil list for me:

  #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk0
   1:                        EFI                         209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh HD            423.6 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
   4:                  Apple_HFS Temp Partition Test ... 74.8 GB    disk0s4
   5:                 Apple_Boot Recovery HD             792.2 MB   disk0s5

Partitions 4 and 5 had a dev version of Lion on them. I have just used Disk utility to delete partitions 4 and 5 and resize partition 2 to fill the space.

This worked - Disk Utility resized the main drive with no problem. So what have I done which is different to you? Well, I resized the main partition from booting into the main partition not the Recovery Partiion. You can resize a partition that you have booted from in Disk Utility.

It makes sense that the recovery partition would "get in the way" if you have booted from it, so I suspect that above suggestion might work for you.

MacOS – Disk Utility says: “Error: This disk doesn’t contain an EFI system partition.”

The default results of diskutil list on a clean Lion installation should be as follows:

mac:~ me$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk0
   1:                        EFI                         209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh HD            499.2 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

My definition of a "clean install of Lion" involves letting Disk Utility from the installer partition the drive as GUID and telling it to use all space as a single partition.

Furthermore, your disk0s1 / EFI partition shouldn't show as partitioned according to disk utility:

mac:~ me$ diskutil info disk0s1
   Device Identifier:        disk0s1
   Device Node:              /dev/disk0s1
   Part of Whole:            disk0
   Device / Media Name:      EFI system partition

   Volume Name:              Not applicable (no file system)

   Mounted:                  Not applicable (no file system)

   File System:              None

   Partition Type:           EFI
   OS Can Be Installed:      No
   Media Type:               Generic
   Protocol:                 SATA
   SMART Status:             Verified

   Total Size:               209.7 MB (209715200 Bytes) (exactly 409600 512-Byte-Blocks)
   Volume Free Space:        Not applicable (no file system)
   Device Block Size:        512 Bytes

   Read-Only Media:          No
   Read-Only Volume:         Not applicable (no file system)
   Ejectable:                No

   Whole:                    No
   Internal:                 Yes
   Solid State:              No

Since your mac will boot, it may be overkill to erase everything and start over, but your EFI partition is hitting a check that Apple built into the Disk Utility, so do know that future updates could have problems and you might be forced to re-do things at a time less convenient if the difference between your system and an expected / Apple generated EFI actually breaks something Apple changes down the road (or when certain expected conditions arise like a firmware password, etc...).

On the flip side - it could be a simple check to alert you of a non-standard EFI and not that your EFI is in some way ever going to break. Can another vendor support your Microsoft EFI? If so, you might be able to leave it as is since it appears you are clearly using tools designed to make proper changes even if Disk Utility isn't able to guarantee the changes are appropriate.

Best Answer

Related Solutions

MacOS – How to resize the Lion partition to fill up the unused space on the drive

MacOS – Disk Utility says: “Error: This disk doesn’t contain an EFI system partition.”

Related Question