mkinitrd

MKINITRD(8)                                                        MKINITRD(8)



NAME
       mkinitrd - creates initial ramdisk images for preloading modules

SYNOPSIS
       mkinitrd [--version] [-v] [-f]
                [--preload=module] [--omit-scsi-modules]
                [--omit-raid-modules] [--omit-lvm-modules]
                [--with=module] [--image-version]
                [--fstab=fstab] [--nocompress]
                [--builtin=module] [--nopivot]
                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,  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
       root filesystem.


OPTIONS
       --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.


       -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.


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


       --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  rec-
              ommended, and will be removed in future versions.


       --omit-lvm-modules
              Do not load any lvm modules, even if /etc/fstab expects them.


       --omit-raid-modules
              Do   not   load   any  raid  modules,  even  if  /etc/fstab  and
              /etc/raidtab expect them.


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


       --preload=module
              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
              necessary.


       -v     Prints out verbose information while creating  the  image  (nor-
              mally 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  SCSI  modules  which  are specified in
              /etc/modules.conf. This option may be used as many times as nec-
              essary.


FILES
       /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.

SEE ALSO
       fstab(5), insmod(1), kerneld(8), lilo(8)


AUTHOR
       Erik Troan <ewt@redhat.com>



4th Berkeley Distribution       Sat Mar 27 1999                    MKINITRD(8)