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 used
At the Ubuntu system
df displays: 60 GB used
Differences between the systems:
Ubuntu: ext3 (created years ago)
Fedora 17: ext4 (created with a vanilla
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.).