Time Machine (Encrypted) Not Auto-Mounting on Boot with 10.14.4

Glad to see I'm not the only one having this problem. Been trying to fix it all day with no solution. I have 2 external encrypted hard drives and they won't auto mount on boot. I have to go into Disk Utility and manually mount them. I thought maybe my drives were failing but no it's the update since this only started happening right after I updated to 10.14.4

Exactly the same here: since 10.14.4, one non-encrypted APFS drive automounts at startup, three Time Machine encrypted HFS+ drives don't. Sometimes one alerts pops up at a later time, asking to authenticate with my user password, to provide access to the drive encryption password stored in the keychain; I imagine this is when a Time Machine backup is initiated. Other than that, I have to open Disk Utility where the drives are shown but their names greyed out. Clicking the Mount button, the drive encryption password was asked the first time IIRC; opting then for this password to be remembered (there was a checkbox for that in the dialog), all the other times after that all that needs to be done is click the Mount button. Still, this needs to be done for each and every drive each time the Mac is rebooted. Probably that doesn't matter, but my Mac internal drive is encrypted too.

I'm having this problem, too. But, to verify, I went ahead and decrypted my Time Machine backup drive (took a couple of days but backups happen during decryption so you're covered if you want to take this route) and it mounted just like normal after a reboot.

So Apple's update has broken encrypted Time Machine backup drive automounting. I'm going to re-encrypt later on and see if creating an /etc/fstab file solves the problem.

Yes, exactly the same problem here too on my MacBook Pro. Won’t mount the 2 time machine external drives automatically. Works fine once I mount manually in disc utility. Problem started immediately after update.

Had to verify with both login password and keychain disc passwords (different passwords) separately for both encrypted backups. After that it hasn’t asked again.

Also, tried adding time machine to the list of permissions in keychain amongst various things with no joy.

I did notice that there were 2 separate CSuseragent entries in the keychain permissions. Could this be important? Bit worried about removing one to check as I wouldn’t know how to re-add it.

Hope a fix is released soon, it’s very annoying!!

Further to my previous post, I went ahead and deleted the keychain entry for both my external hard drives. When I rebooted it requested the keychain password and then the hard drives appeared on my desktop without manually mounting. However, when I rebooted again they didn’t auto mount. I then rebooted without the drives connected and reconnected once open, they appeared without manual mount. Regardless of these minor successes, they obviously still don’t do what they should when already connected.

I’ve also reported this to Apple as an issue. Hopefully they’ll be a fix soon.

I do have the issue on my Mac mini 2018 with an external encrypted hdd formatted with journaled HFS+ for TM backup.

In addition to what is reported in this thread, i.e. no mount on reboot, I found my external TM Backup volume also dismounted when I returned to my MM after not using it for a couple of hours. I reported this issue to AppleCare. To date they have come up with two measures which improved the situation, after a complete reinstall of macOS. Firstly they asked me to delete all files in Library/Caches, Library/LaunchAgents, and Library/LaunchDaemons. In my environment, this reinstated the auto mount of my TM Backup volume. The second recommendation was to disable System Preferences > Energy Saver > 'Put hard disks to sleep when possible' which, plus a restart, kept my TM Backup volume mounted since 30 hours now...

@gdexpert:

I think it would be interesting to understand what makes you not experiencing the issue. Do you have the Energy Saver Hard Disk Sleep option on or off?

So this means the issue is specific to encrypted Time Machine drives. Thanks for the clarification. I filed a bug report at https://developer.apple.com/bug-reporting/ four days ago and it was flagged as duplicate within a few years. So it seems Apple is aware of the issue.

In my first post, I stated that I have an external (spinning) encrypted disk that behaves normally after installing 10.14.4. What I had forgotten is the fact that this drive is an old FireWire 800 drive that is connected via a thunderbolt 2 to firewire adapter.

cfrombth says that he is having issues with both thunderbolt and USB drives.

So it appears to me that the connection type plays a role here.

Anyone having tested an external Thunderbolt 2 drive?

I have a similar problem when trying to do a time machine backup to an Apple Timebox. As far as I know neither my main hard disk nor the Apple Time Box are encrypted disks, though there may be a couple of encrypted folders on the main disk and in some form on the backup.

It claims that there is either some encryption or de-encryption in operation and to please wait. Eventually, anything form 20 mins to a few hours later it allows a backup to occur.

Not sure if this is related to changes in Mojave 10.14.4 but I never saw this problem before that!

Apple called me about this. They've acknowledged that it's a bug and they acknowledged that they can reproduce it internally.

The agent had me repro it on my machine so he could collect additional logs in order to help ensure that the fix Apple develops will cover my configuration as well.

The agent didn't commit to a specific release, but acknowledged that it was not an intentional change and that we should expect a future release of macOS to carry a fix. He also said that leaving the drive unencrypted was the best workaround for now, if it's practical to do so. Otherwise, backup integrity should not be affected by continuing to mount the drive manually under 10.14.4.

I ran into this problem with an external time machine drive and another external hard drive, both formatted as AFPS. I wrote a startup script following these steps to address the problem:

1) plug in your external hard drive and mount with the Disk Utility app (under Applications / Utilities) by selecting the drive from the list in the left side and clicking the Mount icon

2) open Terminal (under Applications / Utilities), type in "diskutil coreStorage list" and press enter

3) each APFS volume will have 4 entries, the first is a "Logical Volume Group", then a "Physical Volume", then a "Logical Volume Family", and finally a "Logical Volume". Copy the identifier following "Logical Volume", it's in the following format (where X can be a number or a letter) XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

4) open the Script Editor App (under Applications/Utilities) and click "New Document" or simply press Cmd + N

5) for each APFS drive you want to mount on startup, enter the following, using the volume identifier copied in step 3:

delay 15

do shell script "diskutil coreStorage unlockVolume XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX -passphrase [volume password]"

[Note] to unlock multiple volumes, simply add " && " followed the above command (using the volume identifier from the second hard drive in step 3):

delay 15

do shell script "diskutil coreStorage unlockVolume XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX -passphrase [volume password] && diskutil coreStorage unlockVolume XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX -passphrase [volume password]"

6) save the script somewhere, then select File / Export; under "File Format" select "Application"; leave everything else blank and save the application somewhere

7) open the System Preferences app (click on the apple menu at the top left of your taskbar), then click on Users & Groups; select your user, then click on the Login Items tab; drag the application you saved in step 6 into the list

8) when you restart your computer, your hard drives should be automatically unlocked and mounted

Whenever apple comes out with another update, I would remove the script from your startup items and see if the issue has been fixed. If not, this should continue to work until Apple resolves the issue.

One observation I want to add, that the pop-up for the disk encryption password eventually pops up on its own within about an hour. I usually use Disk Utility to mount the Time Machine disk on my MacBook, but sometimes I forget, and I eventually get the pop-up.

Since updating to Mojave I have observed the same issue. I have one external 3T drive configured with three partitions, one of which is solely for Time Machine. Upon booting up, only the first two partitions auto-mount. The Time Machine partition has to be mounted in disk utility or if I decide not to mount it manually, in about 10 minutes or so it magically appears. In either case, when it mounts, I have to enter my encryption password.