DOS users are accustomed to defragging their disks every few weeks and some have even developed some ritualistic beliefs regarding defragmentation. None of these habits should be carried over to Linux and ext2. The MS-DOS file system is also known to lose large amounts of disk space due to internal fragmentation. So unlike DOS there is no need to split up large disks into multiple partitions to keep block size down. Use the 1 KB default block size if possible.
Most people use the default.
3.5 File lifetimes and backup cycles as partitioning criteria With ext2, Partitioning decisions should be governed by backup considerations and to avoid external fragmentation from different file lifetimes. Files have lifetimes. After a file has been created, it will remain some time on the system and then be removed. File lifetime varies greatly throughout the system and is partly dependent on the pathname of the file. For backup it is useful if the amount of daily backup is smaller than the capacity of a single backup medium.