MDADM with Encryption without losing files

Question

Current setup is two 4TB hard drives in a RAID 1 setup using MDADM in Debian. Would like to encrypt the MD0 mount with whatever encryption is good. I was going to use something like this:

sudo cryptsetup luksFormat /dev/md0
sudo cryptsetup luksOpen /dev/md0 secure
sudo mkfs.ext4 /dev/mapper/secure

1) From what I understand, this will wipe out my data before encrypting. Is there a way to encrypt my MD0 without losing or moving all the data around? 2) Would the array being encrypted impact the performance of grep/ripgrep commands?

Answer 1

Generally speaking it's not possible with standard linux tools to encrypt in place, that is to encrypt that device while it has data on it, and not lose the data. You'll need to copy it to another media, encrypt and then copy it back.

It will effect performance of all operations on that disk. Now the disk will have to encrypt and decrypt blocks of data to read and write to them which has overhead.