File system Tail packing Transparent compression Block suballocation Allocate-on-flush Extents Variable file block size[lower-alpha 74] Sparse files DECtape Level-D Version 6 Unix file system (V6FS) Version 7 Unix file system (V7FS) FAT12/16/32 GFS HPFS NTFS HFS Plus FFS UFS1 UFS2 LFS ext Xiafs ext2 ext3 ext4 Lustre NILFS ReiserFS Reiser4 OCFS OCFS2 XFS JFS QFS BFS NSS NWFS ODS-5 VxFS UDF Fossil ZFS Btrfs VMFS2 VMFS3 File system Tail packing Transparent compression Block suballocation Allocate-on-flush Extents Variable file block size[lower-alpha 74] Sparse files