Change EXT4 to BTRFS and Merge with Exisiting Volume

Ask Fedora
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1

I have two 2 TB SSDs on my F41 KDE system:

  • The main one is formatted with BTRFS
  • The second one is formatted with EXT4 and used for storing games.

Currently, the main SSD is barely used, so I want to convert the second SSD from EXT4 to BTRFS and then merge it with the main BTRFS volume to create a single 4 TB storage pool.

I there a way to convert the EXT4 SSD to BTRFS and merge it without losing my data / having to reinstall all my games?
Could I simply transfer the data from the EXT4 SSD to the BTRFS SSD, convert the EXT4 SSD to BTRFS, merge the two volumes, and then move the data back to its original location?

2

You cannot convert inplace. As you suggest you can:

  1. backup the ext4 data to the main drive
  2. format the 2nd drive to btrfs

If you want to have btrfs manage both drives in a raid configuration then you do not need to copy the data back. There are btrfs utilities that will balance the data across the to drives. It is worth reading up on this if you are going to run a RAID.

If you want to have the 2nd drive be its own btrfs volume then you would need to restore your backup.