I have a 6TB Seagate formatted to Ext4 connected to my LibreElec machine (Dell Optiplex i5) and a second one formatted to NTFS connected to my Windows laptop and used as a backup. As far as I can tell there are exactly the same files on both (I sync then regularly) but the Ext4 has c400GB less free space than the NTFS one.
Is this normal for an Ext4 drive? If not are there any tools to investigate the difference?