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mkinitrd

NAME

mkinitrd - creates initial ramdisk images for preloading modules

SYNOPSIS

mkinitrd [--version] [-v] [-f]
         [--preload=module] [--with=module]
         [--omit-scsi-modules] [--omit-raid-modules]
         [--omit-ide-modules]
         [--image-version] [--fstab=fstab] [--nocompress]
         [--builtin=module] [--nopivot] [--noudev]
         [--allow-missing] [--tmpdir=tmpdir]
         [--initrdfs=fs] [--dsdt[=dsdt.aml]]
         [--lvm-version=1|2] [--force-usb]
         image kernel-version

DESCRIPTION

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, SCSI modules, USB modules, and raid modules if the system's root partition needs them them, which makes it simple to build and use kernels using modular device drivers.

Any module options specified in /etc/modules.conf or /etc/modprobe.conf are passed to the modules as they are loaded by the initial ramdisk.

If the correct disk driver cannot be detected, mkinitrd will fallback to the modules specified in the scsi_hostadapter line of /etc/modules.conf or /etc/modprobe.conf.

The root filesystem used by the kernel is specified in the boot configuration 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 root filesystem.

OPTIONS

--allow-missing

Do not stop if we cannot find some of the required modules. This may be used when building an initrd for a custom kernel that has those modules builtin.

--builtin=module

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.

--dsdt[=dsdt.aml]

Appends a custom acpi DSDT to the initrd image.

-f

Allows mkinitrd to overwrite an existing image file.

--fstab=fstab

Use fstab to automatically determine what type of filesystem the root device is on. Normally, /etc/fstab is used.

--force-usb

Build an initrd with support for the root filesystem on an usb device and all usb controller drivers.

--image-version

The kernel version number is appended to the initrd image path before the image is created.

--initrdfs=fs

Use the specified fs for the initrd image, overriding the default.

--lvm-version=1|2

Use the specified lvm vesion modules and commands. It only makes sense whith a 2.4 kernel patched to support both lvm versions or when mkinitrd fails in detecting the correct version of lvm.

--nocompress

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 recommended, and will be removed in future versions.

--noudev

Do not create an initrd with basic support for udev.

--omit-raid-modules

Do not load any raid modules, even if we are using root raid.

--omit-scsi-modules

Do not load any scsi modules, including 'scsi_mod' and 'sd_mod' modules, even if they are present.

--omit-ide-modules

Do not load any IDE modules, even if they are present.

--preload=module

Load the module module in the initial ramdisk image. The module gets loaded before any autodetected modules. This option may be used as many times as necessary.

-v

Prints out verbose information while creating the image (normally the mkinitrd runs silently).

--version

Prints the version of mkinitrd that's being used and then exits.

--with=module

Load the modules module in the initial ramdisk image. The module gets loaded after any autodetected modules. This option may be used as many times as necessary.

--tmpdir=tmpdir

Use tmpdir as temporary directory for mkinitrd operations. The underlying filesystem must be capable of doing loopback-mounts, so tmpfs and nfs are not (currently) possible.

FILES

/dev/loop*

A block loopback device is used to create an ext2, ext3 or minix image.

/etc/modprobe.conf

Specifies module options to be used for kernel 2.5 and greater.
 

/etc/modules.conf

Specifies module options to be used for kernel 2.4 and lower.

SEE ALSO

fstab(5), insmod(1), lilo(8), grub(8), lvm(8), mdadm(8), udev(8)

AUTHOR

 Erik Troan <ewt@redhat.com>
 Patches for MandrakeSoft by Guillaume Cottenceau <gc at mandrakesoft.com>,
 Pixel <pixel at mandrakesoft.com> and Luca Berra <bluca at vodka.it>.