Today, after decrypting my encrypted drive, the system failed to boot into it.
I forget what the error said. It maybe said that it could not fine new_root or something.
I tried something like the following, by I don’t know what it does.
cryptsetup reencrypt --decrypt --header new_file device_path
I’m not sure what it does and what the --header part does. It was taking too long, so interrupted with a reboot. Now its saying their device is not a valid LUKS device.
OP, I would seriously consider trying the Arch Wiki for this. I really hope you had a backup, but you probably need expert-level advice here (at least below “paid data recovery specialist”) if you have any hope of unfucking this. Obviously you’ve learned your lesson about running random commands you don’t understand in response to an error message, so I don’t think people should be scolding you for that.
The command had the --decrypt option so I thought that would make it decrypt.
I was following step 1.3 here, in trying to “decrypting LUKS2 devices in-place.”
https://wiki.archlinux.org/title/Removing_system_encryption
This seems reasonable. And you’re right.
But there is absolutely no way that interrupting such an operation with a forced power-cycle can be safe. In fact it’s an almost guaranteed way to put a data partition into a irrecoverable state.
When it comes to storage operations, you either let them fail, or complete. Interrupting file system modifications is a HUGE no-no.