File Vault volumes cannot be resized

Written late in the evening in English • Tags: ,

A couple of months ago Windows Update broke the Windows 7 install on my MacBook Air: the keyboard wouldn’t type anything beyond CTRL+ALT+DEL. Today I tried to fix the problem, but eventually gave up. (I’m not the only one reporting such trouble, but I’m guessing others had automatic login enabled and could fix things with just a mouse.)

Boot Camp Assistant has an option to remove the Windows partition, which I thought was cool. Unfortunately it failed without much detail on how or what or where. Looking at the disk with Disk Utility revealed that the Windows partition was gone, but the free space was still there, sitting unused.

Turns out one has to turn off File Vault to resize the underlying partition. I did that, waited for the conversion to end, and rebooted.

I then tried to resize the Macintosh HD partition to fill the disk, but it failed in the disk verification phase. Running Verify Disk on the Macintosh HD filesystem reported issues with hard links. (I guess this is a typical error that crops up; I’ve written about it before.)

Since Macintosh HD is the boot partition, it cannot be repaired with the system running. The instructions for booting into the recovery partition (press Option+R) didn’t work, but keeping just the Option key pressed during boot brings up the partition list just fine. The Recovery partition is one of those in the list. Disk Utility is the last thing on the list of tasks that comes up.

After fixing the Macintosh HD filesystem, I thought I’d resize the partition as well. However, that failed with an error that it couldn’t unmount the disk. I tried mounting it and resizing again, but got the same error.

I rebooted back into the normal system and restarted Disk Utility. Now resizing the partition succeeded without further problems (and rather quickly). Just to be safe, I ran Verify Disk as well and it reported no apparent issues.

Finally to get back to where I started, but with more space, I turned File Vault back on.