Converting EXT4 to BTRFS, /dev/sda3 is mounted

[MaK11-12]

How do i convert ext4 to btrfs. I have tried "sudo btrfs-convert /dev/sda3/' but it just says '/dev/sda3/ is mounted' .How can i unmount the root filesystem? I have tried 'sudo umount /dev/sda3'. What can i do?

 

[bkifft]

well, you can't unmount the root filesystem. in order to convert it you'd need to boot without it beeing mounted, for example using a live cd (just make sure it contains the btrfs tools, or create your own)