I haven't backed up a few months but since my last backup I activated FileVault which might be now giving some issues. When connecting my external backup disk, no matter how many times I click 'start backup', it will say preparing backup, and then stop.

There is a message that is displayed that suggests it related to the File Vault, but I don't know how to rectify this. File Vault has been implemented for a few months if not longer now, but the message seems to suggest that it hasn't been completed. I'm also not sure whether this is referring to File Vault on the external drive itself, which I'm not sure how to check.

MBP* said:

I'm also not sure whether this is referring to File Vault on the external drive itself,

As you have realised, it is saying that TM can't backup because the FileVault encryption (or decryption) process on the system disk has not completed.

You can see the current state and progress of encryption with the Terminal command: diskutil apfs list. What does that say about FileVault and encryption?

MBP* said:

File Vault has been implemented for a few months if not longer now,

If I am reading you correctly File Vault encryption was turned on months ago and it never completed? Not a file vault expert but the first thing that comes to mind is to turn if off. When that is completed turn it back on and wait until it is completed before attempting the TM backup.

HDFan said:

Not a file vault expert but the first thing that comes to mind is to turn if off.

If it really has not completed (check with Terminal command 2 posts back, and also in System Preferences), then I would be worried about the integrity of your disk. First step is to make some sort of backup - even if that is just to copy (with Finder) your home directory to another disk.

This doesn't solve the problem, but...
... do you really need filevault on the backup?

Do you carry the backup around (that might justify it), or... do you just keep it in a certain location?
If the latter, I'd leave the backup UNencrypted, and locked up or hidden.

The problem with encrypting a backup drive is... in that "moment of extreme need" when you REACH FOR the backup... and then find that the encryption is preventing YOU from getting at the data... well... there's the problem.

gilby101 said:

As you have realised, it is saying that TM can't backup because the FileVault encryption (or decryption) process on the system disk has not completed.

You can see the current state and progress of encryption with the Terminal command: diskutil apfs list. What does that say about FileVault and encryption?

I have done this, and this is the output:

Container disk1 DA1B71CB-26FC-4508-B49E-573AFC395AFE ==================================================== APFS Container Reference: disk1 Size (Capacity Ceiling): 959882506240 B (959.9 GB) Capacity In Use By Volumes: 894610853888 B (894.6 GB) (93.2% used) Capacity Not Allocated: 65271652352 B (65.3 GB) (6.8% free) | +-< Physical Store disk0s2 B650C15E-4D1D-4E18-A437-6E255BCD1AC3 | ----------------------------------------------------------- | APFS Physical Store Disk: disk0s2 | Size: 959882506240 B (959.9 GB) | +-> Volume disk1s1 FDEBFACE-9524-47F4-B05F-90B76B93A47B | --------------------------------------------------- | APFS Volume Disk (Role): disk1s1 (Data) | Name: Macintosh HD - Data (Case-insensitive) | Mount Point: /System/Volumes/Data | Capacity Consumed: 862265483264 B (862.3 GB) | Sealed: No | FileVault: Yes (Unlocked) | +-> Volume disk1s2 07B1DC3B-A9C3-46B7-B413-F9D6EFC1E9E1 | --------------------------------------------------- | APFS Volume Disk (Role): disk1s2 (Preboot) | Name: Preboot (Case-insensitive) | Mount Point: /System/Volumes/Preboot | Capacity Consumed: 294965248 B (295.0 MB) | Sealed: No | FileVault: No | +-> Volume disk1s3 97F366DB-C2D6-4277-AD6F-E52EDD64A79F | --------------------------------------------------- | APFS Volume Disk (Role): disk1s3 (Recovery) | Name: Recovery (Case-insensitive) | Mount Point: /Volumes/Recovery | Capacity Consumed: 613638144 B (613.6 MB) | Sealed: No | FileVault: No | +-> Volume disk1s4 4EAFD767-2331-47DD-9596-75CBE82728FF | --------------------------------------------------- | APFS Volume Disk (Role): disk1s4 (VM) | Name: VM (Case-insensitive) | Mount Point: /System/Volumes/VM | Capacity Consumed: 16108163072 B (16.1 GB) | Sealed: No | FileVault: No | +-> Volume disk1s5 610A3661-6F3A-45A0-AF7A-C1E119108DA8 -------------------------------------------------- APFS Volume Disk (Role): disk1s5 (System) Name: Macintosh HD (Case-insensitive) Mount Point: /System/Volumes/Update/mnt1 Capacity Consumed: 15051403264 B (15.1 GB) Sealed: Broken FileVault: Yes (Unlocked) Encrypted: No | Snapshot: DF9B3210-34B6-48C8-9790-202D1FF3E9EC Snapshot Disk: disk1s5s1 Snapshot Mount Point: / Snapshot Sealed: Yes

HDFan said:

If I am reading you correctly File Vault encryption was turned on months ago and it never completed? Not a file vault expert but the first thing that comes to mind is to turn if off. When that is completed turn it back on and wait until it is completed before attempting the TM backup.

I don't think it's incomplete, otherwise I would've expected it to tell me? I log into the machine with my password to unencrypt it so I assume that the encryption has worked successfully - otherwise a guess the whole logon would've hanged.

Fishrrman said:

This doesn't solve the problem, but...
... do you really need filevault on the backup?

Do you carry the backup around (that might justify it), or... do you just keep it in a certain location?
If the latter, I'd leave the backup UNencrypted, and locked up or hidden.

The problem with encrypting a backup drive is... in that "moment of extreme need" when you REACH FOR the backup... and then find that the encryption is preventing YOU from getting at the data... well... there's the problem.

Click to expand...

Lots of sensitive files on both the laptop and the backup drive so this is essential. I've had the encryption on both devices for many years. I think after replacing my HD a year ago is what caused a bit of a hiccup in this process which Im trying to revert to.

MBP* said:

APFS Volume Disk (Role): disk1s5 (System) Name: Macintosh HD (Case-insensitive) Mount Point: /System/Volumes/Update/mnt1 Capacity Consumed: 15051403264 B (15.1 GB) Sealed: Broken FileVault: Yes (Unlocked) Encrypted: No

Your `diskutil apfs list` looks good with one exception.
There does not seem to be anything with partially encrypted FileVault. But I am concerned about the mount point for the 15GB System volume. That is not normal. Makes me think that your system has an incomplete update - but I don't know for sure. It does make sense that TM will not run with an incomplete update, but the TM error message is then all wrong.

My suggestion (and it is only a suggestion):
1) Copy (drag and drop in Fonder) all important data to another disk, along with /Applications and your ~/Library folder. This is just in case you have a disaster in what follows!
2) Try and remove FileVault and let the decryption complete. Use diskutil apfs list to track the progress until complete.
3) Reinstall macOS without erasing anything.

Thanks for the response.
What should size should this be?

I will try you suggestion, but perhaps try TM again before any reinstallation of the OS. Will the OS reinstall without removing any files? When copy and pasting apps, does this allow reinstallation of these app later by dragging them back?

Not sure if related, but I recently needed to connect via Ethernet to do my initial backup. After that it was fine.

MBP* said:

I will try you suggestion, but perhaps try TM again before any reinstallation of the OS. Will the OS reinstall without removing any files? When copy and pasting apps, does this allow reinstallation of these app later by dragging them back?

Something is wrong with your system, but normally macOS will reinstall without removing files. But with yours I don't know. With some apps copying apps back to /Applications works though you will loose settings etc. For others, you need to go to reinstall.
Worst case is that you need to erase, reinstall and recover what you can - hence my suggestion of copying as much as possible to another disk.

An alternative is to try a different backup utility (e.g. Carbon Copy Cloner) which if it works would give you a complete recovery following erase and reinstall macOS.