How to stop FileVault (its encrypting my data since months) - OSX Yosemite

If this old Mac is using a hard drive, then that hard drive may be failing or there is a file system issue (the latter cannot be fixed until the encryption process finishes). Or maybe you have a software issue which is causing the drive to be accessed so that the encryption process is taking longer than it should....in this case try booting into Safe Mode to see if it helps with the encryption process. You do have to have the laptop connected to the charger in order for the Filevault encryption process to work, otherwise the encryption will be paused.

To check the health of the drive, run DriveDx (free trial period) and post the complete text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar.

Thanks to Bob Harris...

FileVault encryption will continue across reboots, sleeps, etc...

FileVault disable in the middle of encrypting via Applications -> Utilities -> Terminal session, but be aware that it is going to then proceed to decrypt everything it has already encrypted, so this going to be just as slow.

sudo fdesetup disable

Password: <your admin password>

Mac stuck on encrypting with FileVault - Apple Community

The SSD looks Ok.

I would add to @daniel Azuelos' suggestion to also boot into Safe Mode as well so that third party software does not launch automatically during boot & login (mentioned it in my earlier post). This will keep any anti-virus apps, cleaning/optimizer apps, and third party security software from interfering & slowing down the encryption process.

I also highly recommend you make a good backup if you don't already have one. If the encryption process cannot be resumed or completed, then your only option would be to wipe the entire physical SSD followed by reinstalling macOS & restoring from a backup. I don't believe it is possible to stop & reverse the encryption process once it has begun.

Maybe even disconnect all external devices as well just in case one of them is causing a problem here.

What is the condition of the laptop's battery? I wonder if it is showing "Service Battery" or "Replace Now" condition and whether that could prevent Filevault from finishing even if the power adapter is connected?

The message:

    Conversion Progress:   Paused

could come from 2 blocking events:

1. Your MacBook is not plugged into a power supply.
2. Another process is simply accessing your disk as FileVault

does and they are in a mutual conflict for this access.

One of these processes is Spotlight.

You can easily turn it completly off:

1. 1.   Open Terminal,
   2.   Copy the following command:

       /usr/bin/sudo mdutil -i off /

paste it in the Terminal window, and enter your password ( you won't see it ) and then hit [return],

3.    A few minutes later copy-paste the following command in Terminal:

       diskutil cs list | grep 'Conversion Progress:'

See this other post on the same kind of problem but with a different version of macOS:

FileVault functionning and tuning? - Apple Community

If you are at ease with Terminal commands, and want to further investigate this problem,

feel free to tell.

Forgive me this stupid question:

is the power supply plugged in?

I don't believe there is a way to stop it, how far along is it?

Filevault state, open Terminal & paste these in & press enter…

    fdesetup status

    diskutil cs list | grep 'Conversion Progress'

You can try booting into Safe Mode and let the computer sit idle to see what happens, just make sure the power adapter is connected and recognized by macOS. I don't know how long it will take before Filevault may resume encrypting.

Another option to rule out macOS issues is maybe try booting into Recovery Mode and make sure the "Data" volume is mounted. Then let the computer side idle in Recovery Mode to see if Filevault encryption resumes.

I have seen other people on this forum report Filevault encryption/decryption becoming paused over the years....I don't recall any of them were ever able to get the process to resume, so be prepared for that outcome. We don't always get a lot of details and rarely get much information about the specific setups of their systems & configurations which may have impacted things.

In Terminal, type:

top -o cpu -s 15 | egrep 'halted|stopped|stuck|unknown|PID'

If you get a process repeated many times, copy the full line and paste it here ( as code for readability ).