mkinitrd - creates initial ramdisk images for preloading modules
mkinitrd [--version] [-v] [-f]
mkinitrd creates filesystem images which are suitable for use as Linux
initial ramdisk (initrd) images. Such images are often used for
preloading the block device modules (such as IDE, SCSI or RAID) which
are needed to access the root filesystem. mkinitrd automatically loads
filesystem modules (such as ext3 and jbd), IDE modules, all
scsi_hostadapter entries in /etc/modules.conf, and raid modules if the
system's root partition is on raid, which makes it simple to build and
use kernels using modular device drivers.
Any module options specified in /etc/modules.conf are passed to the
modules as they are loaded by the initial ramdisk.
If the root device is on a loop device (such as /dev/loop0), mkinitrd
will build an initrd which sets up the loopback file properly. To do
this, the fstab must contain a comment of the form:
# LOOP0: /dev/hda1 vfat /linux/rootfs
LOOP0 must be the name of the loop device which needs to be configured,
in all capital lettes. The parameters after the colon are the device
which contains the filesystem with the loopback image on it, the
filesystem which is on the device, and the full path to the loopback
image. If the filesystem is modular, initrd will automatically add the
filesystem's modules to the initrd image.
The root filesystem used by the kernel is specified in the boot config-
uration file, as always. The traditional root=/dev/hda1 style device
specification is allowed. If a label is used, as in root=LABEL=rootPart
the initrd will search all available devices for an ext2 or ext3
filesystem with the appropriate label, and mount that device as the
Act as if module is built into the kernel being used. mkinitrd
will not look for this module, and will not emit an error if it
does not exist. This option may be used multiple times.
-f Allows mkinitrd to overwrite an existing image file.
Use fstab to automatically determine what type of filesystem the
root device is on. Normally, /etc/fstab is used.
The kernel version number is appended to the initrd image path
before the image is created.
Normally the created initrd image is compressed with gzip. If
this option is specified, the compression is skipped.
--nopivot Do not use the pivot_root system call as part of the
initrd. This lets mkinitrd build proper images for Linux 2.2
kernels at the expense of some features. In particular, some
filesystems (such as ext3) will not work properly and filesystem
options will not be used to mount root. This option is not rec-
ommended, and will be removed in future versions.
Do not load any lvm modules, even if /etc/fstab expects them.
Do not load any raid modules, even if /etc/fstab and
/etc/raidtab expect them.
Do not load any scsi modules, including 'scsi_mod' and 'sd_mod'
modules, even if they are present.
Load the module module in the initial ramdisk image. The module
gets loaded before any SCSI modules which are specified in
/etc/modules.conf. This option may be used as many times as
-v Prints out verbose information while creating the image (nor-
mally the mkinitrd runs silently).
Prints the version of mkinitrd that's being used and then exits.
Load the modules module in the initial ramdisk image. The module
gets loaded after any SCSI modules which are specified in
/etc/modules.conf. This option may be used as many times as nec-
/dev/loop* A block loopback device is used to create the
image, which makes this script useless on systems
without block loopback support available.
/etc/modules.conf Specified SCSI modules to be loaded and module
options to be used.
fstab(5), insmod(1), kerneld(8), lilo(8)
Erik Troan <firstname.lastname@example.org>
4th Berkeley Distribution Sat Mar 27 1999 MKINITRD(8)