.I bytes-per-inode
]
[
+.B \-I
+.I inode-size
+]
+[
.B \-j
]
[
following extended options are supported:
.RS 1.2i
.TP
-.BI stride= stripe-size
+.BI stride= stride-size
Configure the filesystem for a RAID array with
-.I stripe-size
-filesystem blocks per stripe.
+.I stride-size
+filesystem blocks. This is the number of blocks read or written to disk
+before moving to next disk. This mostly affects placement of filesystem
+metadata like bitmaps at
+.BR mke2fs (2)
+time to avoid placing them on a single disk, which can hurt the performanace.
+It may also be used by block allocator.
+.TP
+.BI stripe-width= stripe-width
+Configure the filesystem for a RAID array with
+.I stripe-width
+filesystem blocks per stripe. This is typically be stride-size * N, where
+N is the number of data disks in the RAID (e.g. RAID 5 N+1, RAID 6 N+2).
+This allows the block allocator to prevent read-modify-write of the
+parity in a RAID stripe if possible when the data is written.
.TP
.BI resize= max-online-resize
Reserve enough space so that the block group descriptor table can grow
to support a filesystem that has max-online-resize blocks.
+.TP
+.B test_fs
+Set a flag in the filesystem superblock indicating that it may be
+mounted using experimental kernel code, such as the ext4dev filesystem.
.RE
.TP
.BI \-f " fragment-size"
.B \-F
Force
.B mke2fs
-to run, even if the specified device is not a
-block special device, or appears to be mounted.
+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
+.B 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.
.TP
.BI \-g " blocks-per-group"
Specify the number of blocks in a block group. There is generally no
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.
+.TP
+.BI \-I " inode-size"
+Specify the size of each inode in bytes.
+.B mke2fs
+creates 256-byte inodes by default. In kernels after 2.6.10 and some
+earlier vendor kernels it is possible to utilize inodes larger than
+128-bytes to store
+extended attributes for improved performance. The
+.I inode-size
+value must be a power of two larger or equal to 128. The larger the
+.I inode-size
+the more space the inode table will consume, and this reduces the usable
+space in the filesystem and can also negatively impact performance.
+Extended attributes
+stored in large inodes are not visible with older kernels, and such
+filesystems will not be mountable with 2.4 kernels at all. It is not
+possible to change this value after the filesystem is created.
.TP
.B \-j
Create the filesystem with an ext3 journal. If the
@JDEV@.I external-journal
@JDEV@must have been created with the
@JDEV@same block size as the new filesystem.
+@JDEV@In addition, while there is support for attaching
+@JDEV@multiple filesystems to a single external journal,
+@JDEV@the Linux kernel and
+@JDEV@.BR e2fsck (8)
+@JDEV@do not currently support shared external journals yet.
@JDEV@.IP
@JDEV@Instead of specifying a device name directly,
@JDEV@.I external-journal
pseudo-filesystem feature "none" will clear all filesystem features.
.RS 1.2i
.TP
+.B large_file
+Filesystem can contain files that are greater than 2GB. (Modern kernels
+set this feature automatically when a file > 2GB is created.)
+.TP
.B dir_index
Use hashed b-trees to speed up lookups in large directories.
.TP
.BI \-T " fs-type"
Specify how the filesystem is going to be used, so that
.B mke2fs
-can choose optimal filesystem parameters for that use, as defined
-filesystem type configuration settings found in the
-.BR /etc/mke2fs.conf (5)
-file.
+can choose optimal filesystem parameters for that use. The filesystem
+types that are can be supported are defined in the configuration file
+.BR /etc/mke2fs.conf (5).
+The default configuration file contains definitions for the filesystem
+types: small, floppy, news, largefile, and largefile4.
.TP
.B \-v
Verbose execution.
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff