cryptsetup online reencrypt returns "This operation is not supported for this device type."

Question

I have a LUKS device opened on top of a logical volume, and I'd like to do an online reencryption for the LUKS device.

I did cryptsetup reencrypt --active-name <LUKS2 device>, and it gives me This operation is not supported for this device type.

I searched the error message in cryptsetup gitlab repo, and I suspect the failure reason might be that USE_LUKS2_REENCRYPTION is undefined, but I couldn't find any place to enable the online reencrypt code.

Does anyone know if what I suspect is correct, or how to enable that macro? Thanks!

FWIW, I'm on cryptsetup 2.2.2, the device was encrypted with LUKS2, and the linux distro is Ubuntu 20.04.4.

I tried different ways to run the reencrypt command like using the logical volume name, but ended up with the same error.

I'm expecting this command to be passed.

Answer 1

You probably are using LUKS1, this function only works in LUKS2. Enable LUKS2 with this command sudo cryptsetup convert --type luks2 /dev/mapper/disk9 or whatever your disk is.