Enlarge disks by removing reserve space on ext2/3/4

Five percent of a ext2/3/4 filesysteem is reserved for root.

• With tune2fs this can be tweaked, even after the filesystem is created.

# tune2fs -m 1 /dev/sda1

this reserves 1 percent.

# tune2fs -m 0.2 /dev/sda1

this reserves 0.2 percent

• On a filesystem that has no systemfiles, like homedirs, there is no use for any reserved space. You can make this 0 percent.