Justin Williams

Removing Unremovable Files after Upgrading to macOS Catalina

Against the better judgement of my own common sense, I decided to update my iMac to the macOS Catalina beta recently. One of the major internal changes in going from Mojave to Catalina is the transition to a read-only System volume. During this process, I ended up with a folder on my desktop of files that the upgrade was unable to handle. Most of these files seemed innocuous, and I just deleted them. There was one folder, however, that I couldn’t delete because the system claimed it wasn’t empty. Blowing it out via the Finder or the Terminal was a fruitless task.

In the interest of saving you time if you run into this scenario, these are the steps I took to solve my issue.

  1. Reboot your Mac into Recovery Mode. Authenticate your user account if required.
  2. From the menu bar, open the Terminal application.
  3. Disable System Integrity Protection and reboot: csrutil disable; reboot .
  4. Once your Mac reboots (and assuming it's still not in recovery mode), open the Terminal app.
  5. You need to mount the new file system as read-write temporarily so we can blow the folder(s) away: sudo mount -uw /. This is temporary, and rebooting will revert back to the safer read-only variant.
  6. Delete the files you want to purge via the rm command. You’ll probably need to use sudo.
  7. As a last step, you need to re-enable System Integrity Protection. To do that, reboot back into Recovery mode.
  8. From the Recovery Mode menu bar, open the Terminal application: csrutil enable; reboot

Once the reboot completes, your Mac should be back to the expected state, just with a few less zombie folders. You can verify SIP is active by opening Terminal and executing the csrutil status command.

Filed under

Updating Your APFS Encrypted Volume / FileVault Password

For as long as I can remember, I have been running into an annoying issue with my iMac where I’d have to authenticate twice upon restart: once with my old account password to unlock FileVault, followed by my new account password to actually get into my account. I finally took the time to figure out how to fix this the other day. I couldn’t find a succinct example on The Google, so here you go. Note that this is for an APFS volume on High Sierra (10.13). If you are using HFS+ or an older version of macOS still, the instructions may be a bit different.

In Terminal run the following command:

sudo fdesetup list -extended

This will return a list of accounts that are associated with your Mac. The output should look something along the lines of below.

ESCROW  UUID                                  TYPE          USER
        C20A4763-D4F8-4B3C-A889-0021B0735248  OS User       justin
        7DA69D0C-BA82-4575-AC68-CFE037778BA1  Unknown User
        05E65DD7-AE83-4BD4-8B8B-AADA35A307E1  iCloud User

Copy the UUID for your specific user account as you will need it for the next command.

Once again in Terminal, type the following command:

diskutil apfs changePassphrase disk1s1 -user [UUID]

Replace UUID with your UUID you copied from above, obviously. You’ll be asked to enter your old passphrase, followed by the new one. After that, you should be able to sign into your Mac and unlock FileVault using the same password, once more.

Filed under