I almost forgot that most file systems under Linux (e.g. ext4) are mostly set to reserve 5% of every created file system for privileged users. While this is useful on your root file system if your HD is full but you still want to be able to login as root it’s not too useful on usb sticks / pure storage devices.
Anyway I want more space on my usb stick, let’s see what we can do on my stick:
Here we see the default reservation of 5%:
# df -h /dev/sdd1 Filesystem Size Used Avail Use% Mounted on /dev/sdd1 29G 11G 17G 40% /foo
Now we change that value to 0%:
# tune2fs -m 0 /dev/sdd1 tune2fs 1.42-WIP (02-Jul-2011) Setting reserved blocks percentage to 0% (0 blocks)
Et voilà, 1GB more space to waste:
# df -h /dev/sdd1 Filesystem Size Used Avail Use% Mounted on /dev/sdd1 29G 11G 18G 38% /foo
Please note that these 5% reservation is also used to avoid fragmentation of the partition (see man tune2fs).