Copyright 1993, 1994, 1995 by Theodore Ts'o. All Rights Reserved.
This file may be copied under the terms of the GNU Public License.
@JDEV@[
@JDEV@.B -J
@JDEV@.I journal-options
@JDEV@]
@JDEV@[ @JDEV@.B -L @JDEV@.I volume-label @JDEV@] @JDEV@[ @JDEV@.B -n @JDEV@] @JDEV@[ @JDEV@.B -q @JDEV@] @JDEV@[ @JDEV@.B -v @JDEV@] @JDEV@.I external-journal @JDEV@[ @JDEV@.I blocks-count @JDEV@]
-b " block-size" Specify the size of blocks in bytes. Valid block size vales are 1024, 2048 and 4096 bytes per block. If omitted, mke2fs block-size is determined by the file system size and the expected usage of the filesystem (see the -T option).
-c Check the device for bad blocks before creating the file system, using a fast read-only test.
-f " fragment-size" Specify the size of fragments in bytes.
-F Force mke2fs to run, even if the specified device is not a block special device, or appears to be mounted.
-i " bytes-per-inode" Specify the bytes/inode ratio. mke2fs creates an inode for every bytes-per-inode bytes of space on the disk. The larger the bytes-per-inode ratio, the fewer inodes will be created. This value generally shouldn't be smaller than the blocksize of the filesystem, since then too many inodes will be made. Be warned that is not possible to expand the number of inodes on a filesystem after it is created, so be careful deciding the correct value for this parameter.
-j Create the filesystem with an ext3 journal. If the -J option is not specified, the default journal parameters will be used to create an appropriately sized journal (given the size of the filesystem) stored within the filesystem. Note that you must be using a kernel which has ext3 support in order to actually make use of the journal.
-J " journal-options" Create the ext3 journal using options specified on the command-line. Journal options are comma separated, and may take an argument using the equals ('=') sign. The following journal options are supported:
size= journal-size Create a journal stored in the filesystem of size journal-size megabytes. The size of the journal must be at least 1024 filesystem blocks (i.e., 1MB if using 1k blocks, 4MB if using 4k blocks, etc.) and may be no more than 102,400 filesystem blocks. The journal must fit within the newly created filesystem. @JDEV@.TP @JDEV@.BI device= external-journal @JDEV@Attach the filesystem to the journal block device located on @JDEV@.IR external-journal . @JDEV@The external @JDEV@journal must already have been created using the command @JDEV@.IP @JDEV@.B mke2fs -O journal_dev @JDEV@.I external-journal @JDEV@.IP @JDEV@Note that @JDEV@.I external-journal @JDEV@must have been created with the @JDEV@same block size as the new filesystem. @JDEV@.IP @JDEV@Instead of specifying a device name directly, @JDEV@.I external-journal @JDEV@can also be specified by either @JDEV@.BI LABEL= label @JDEV@or @JDEV@.BI UUID= UUID @JDEV@to locate the external journal by either the volume label or UUID @JDEV@stored in the ext2 superblock at the start of the journal. Use @JDEV@.BR dumpe2fs (8) @JDEV@to display a journal device's volume label and UUID. See also the @JDEV@.B -L @JDEV@option of @JDEV@.BR tune2fs (8).
-l " filename" Read the bad blocks list from filename .
-L Set the volume label for the filesystem.
-m " reserved-blocks-percentage" Specify the percentage of the filesystem blocks reserved for the super-user. This value defaults to 5%.
-M Set the last mounted directory for the filesystem. This might be useful for the sake of utilities that key off of the last mounted directory to determine where the filesytem should be mounted.
-n causes mke2fs to not actually create a filesystem, but display what it would do if it were to create a filesystem.
-N " number-of-inodes" overrides the default calculation of the number of inodes that should be reserved for the filesystem (which is based on the number of blocks and the bytes-per-inode ratio). This allows the user to specify the number of desired inodes directly.
-o " creator-os" Manually override the default value of the "creator os" field of the filesystem. Normally the creator field is set by default to the native OS of the mke2fs executable.
"-O feature[,...]" Create filesystem with given features (filesystem options). Currently, the sparse_super and filetype features are turned on by default unless mke2fs is run on a system with a pre-2.2 Linux kernel. Filesystems that may need to mounted on pre-2.2 kernels should be created with "-O none" (or "-r 0" for 1.2 kernels) which will disable these features, even if mke2fs is run on a system which can support them. The following filesystem options are supported:
sparse_super Create a filesystem with fewer superblock backup copies (saves space on large filesystems).
filetype Store file type information in directory entries.
has_journal Create an ext3 journal (as if using the -j option). @JDEV@.TP @JDEV@.B journal_dev @JDEV@Create an external ext3 journal on the given device @JDEV@instead of a regular ext2 filesystem. @JDEV@Note that @JDEV@.I external-journal @JDEV@must be created with the same @JDEV@block size as the filesystems that will be using it.
-q Quiet execution. Useful if mke2fs is run in a script.
-r " revision" Set the filesystem revision for the new filesystem. Note that 1.2 kernels only support revision 0 filesystems. The default is to create revision 1 filesystems.
-R " raid-options" Set raid-related options for the filesystem. Raid options are comma separated, and may take an argument using the equals ('=') sign. The following options are supported:
stride= stripe-size Configure the filesystem for a RAID array with stripe-size filesystem blocks per stripe.
-S Write superblock and group descriptors only. This is useful if all of
the superblock and backup superblocks are corrupted, and a last-ditch
recovery method is desired. It causes
mke2fs to reinitialize the
superblock and group descriptors, while not touching the inode table
and the block and inode bitmaps. The
e2fsck program should be run immediately after this option is used, and there
is no guarantee that any data will be salvageable. It is critical to
specify the correct filesystem blocksize when using this option,
or there is no chance of recovery.
.TP
.BI -t " test"
Check the device for bad blocks before creating the file system
using the specified test.
-T " fs-type" Specify how the filesystem is going to be used, so that mke2fs can chose optimal filesystem parameters for that use. The supported filesystem types are:
1.2i news one inode per 4kb block
largefile one inode per megabyte
largefile4 one inode per 4 megabytes
-v Verbose execution.
-V Print the version number of mke2fs and exit.
There may be other ones. Please, report them to the author.