Confused about command line options for Linux mkfs

I am formatting a new drive on Ubuntu 20.04, and I am at the step where I format the drive to ext4. One article ( says to do this:

sudo mkfs.ext4 -F /dev/sdb1

The article doesn’t say what the -F option is, and there is no -F option in the Linux man page for mkfs at

Another article ( says to use the -L option:

sudo mkfs.ext4 -L datapartition /dev/sda1

but again it doesn’t say what -L does.

Another article ( said to use the -t option

sudo mkfs -t ext4 /dev/sdb

-t is listed on the Linux man page with this: "Specify the type of filesystem to be built. If not specified, the default filesystem type (currently ext2) is used." I don’t want ext2, I want ext4.

So my question is: do I want to choose -F, -L or -t? Where can I find an explanation of those other command line options shown above that are not covered in the Linux man page for mkfs?

Asked By: RTC222


You need to read the correct manpage with man mkfs.ext4 or online where these options are explained:

    Force mke2fs to create a filesystem, even if the specified device is not a 
    partition on a block special device, or if other parameters do not make sense.
    In order to force mke2fs to create a filesystem even if the filesystem
    appears to be in use or is mounted (a truly dangerous thing to do), this
    option must be specified twice. 

-L new-volume-label
    Set the volume label for the filesystem to new-volume-label. The maximum
    length of the volume label is 16 bytes. 

-t fs-type
    Specify the filesystem type (i.e., ext2, ext3, ext4, etc.) that is to be
    created. If this option is not specified, mke2fs will pick a default either
    via how the command was run (for example, using a name of the form mkfs.ext2,
    mkfs.ext3, etc.) or via a default as defined by the /etc/mke2fs.conf(5) file.
    This option controls which filesystem options are used by default, based on
    the fstypes configuration stanza in /etc/mke2fs.conf(5).
Answered By: mook765