mkfs.ext3
OPTIONS
-b block-size
Specify the size of blocks in bytes. Valid block-size values are 1024, 2048 and 4096 bytes per block. If omitted, block-size is heuristically determined by the filesystem size and
the expected usage of the filesystem (see the -T option). If block-size is preceded by a negative sign ('-'), then mke2fs will use heuristics to determine the appropriate block size,
with the constraint that the block size will be at least block-size bytes. This is useful for certain hardware devices which require that the blocksize be a multiple of 2k.
-c Check the device for bad blocks before creating the file system. If this option is specified twice, then a slower read-write test is used instead of a fast read-only test.
-C cluster-size
Specify the size of cluster in bytes for filesystems using the bigalloc feature. Valid cluster-size values are from 2048 to 256M bytes per cluster. This can only be specified if the
bigalloc feature is enabled. (See the ext4 (5) man page for more details about bigalloc.) The default cluster size if bigalloc is enabled is 16 times the block size.
-D Use direct I/O when writing to the disk. This avoids mke2fs dirtying a lot of buffer cache memory, which may impact other applications running on a busy server. This option will
cause mke2fs to run much more slowly, however, so there is a tradeoff to using direct I/O.