I backed up/restored a filesystem from a Ubuntu system to a Fedora 17 one. I noticed that according to df output the used space increased by 30 %. What could be the reasons for this?At the Fedora system df displays: 78 GB usedAt the Ubuntu system df displays: 60 GB usedDifferences between the systems:Ubuntu: ext3 (created years ago)Fedora 17: ext4 (created with a vanilla mkfs.ext4 call)Restoring to an XFS filesystem (on Fedora 17) yields 78 GB used space.Backup and restore was done with GNU tar. The filesystem contains a wide range of different sorts of files (i.e. from source trees, maildirs to ISO's etc.).
What is the space overhead of different filesystems?
filesystems