update-initramfs(8) [debian man page]

UPDATE-INITRAMFS(8)					      update-initramfs manual					       UPDATE-INITRAMFS(8)

NAME

       update-initramfs - generate an initramfs image

SYNOPSIS

       update-initramfs -c|-d|-u [-k version] [-t] [-v] [-b] [-h]

DESCRIPTION

       The  update-initramfs  script manages your initramfs images on your local box.  It keeps track of the existing initramfs archives in /boot.
       There are three modes of operation create, update or delete.  You must at least specify one of those modes.

       The initramfs is a gzipped cpio archive.  At boot time, the kernel unpacks that archive into RAM disk, mounts and uses it as  initial  root
       file system. All finding of the root device happens in this early userspace.

OPTIONS

	-k  version
	      Set  the	specific  kernel  version for whom the initramfs will be generated.  For example the output of uname -r for your currently
	      running kernel.  This argument is optional for update. The default is the latest kernel version.

	      The use of "all" for the version string specifies update-initramfs to execute the chosen action for all kernel  versions,  that  are
	      already known to update-initramfs.

	-c    This mode creates a new initramfs.

	-u    This mode updates an existing initramfs.

	-d    This mode removes an existing initramfs.

	-t    Allows one to take over an custom initramfs with a newer one.

	-v    This option increases the amount of information you are given during the chosen action.

	-b    Set an different bootdir for the image creation.

	-h    Print a short help page describing the available options in update-initramfs.

EXAMPLES

       Update the initramfs of the newest kernel:

       update-initramfs -u

       Create the initramfs for a specific kernel:

       update-initramfs -c -k 2.6.18-1-686

FILES

       /etc/initramfs-tools/update-initramfs.conf

AUTHOR

       The initramfs-tools are written by Maximilian Attems <maks@debian.org>, Jeff Bailey <jbailey@raspberryginger.com> and numerous others.

SEE ALSO

	initramfs.conf(5), initramfs-tools(8), mkinitramfs(8).

Linux								    2008/12/19						       UPDATE-INITRAMFS(8)

INITRAMFS.CONF(5)					       initramfs.conf manual						 INITRAMFS.CONF(5)

NAME

       initramfs.conf - configuration file for mkinitramfs

DESCRIPTION

       The behaviour of mkinitramfs can be modified by its configuration file.

       Each  line in the file can be a configuration variable, a blank line, or a comment. The value of an variable is assigned by an statement of
       the form: name=[value]

       Configuration options can be broken out into configuration snippets and placed in individual files in  the  /etc/mkinitramfs/conf.d  direc-
       tory.   Files in this directory are always read after the main configuration file, so you can override the settings in the main config file
       without editing it directly.

GENERAL VARIABLES

	MODULES
	      Specifies the modules for the initramfs image.

	      Modules listed in /etc/initramfs-tools/modules and /usr/share/initramfs-tools/modules.d/* are always included in the initramfs,  and
	      are loaded early in the boot process.

	      list doesn't load any additional modules at boot time, other than those listed in the above files.

	      most adds most file system, all ata, sata, scsi and usb drivers.

	      dep tries to guess which modules are necessary for the running box and only adds those modules.

	      netboot adds the base and network modules, but skips block devices.

	      The default setting is most.

	BUSYBOX
	      Include  busybox	utilities  for	the boot scripts.  If set to 'n' mkinitramfs will build an initramfs without busybox.  Beware that
	      many boot scripts need busybox utilities.

	COMPRESS
	      Specifies the compression method used for the initramfs image.  mkinitramfs will default to gzip if the kernel lacks  support  (CON-
	      FIG_RD) or the corresponding userspace utility is not present.

	UMASK Set the umask value of the generated initramfs file.  Useful to not disclose eventual keys.

	COMPCACHE_SIZE
	      Amount of RAM to use for RAM-based compressed swap space.  The default is not to use compcache.

	      An empty value - compcache isn't used, or added to the initramfs at all.

	      An integer and K (e.g. 65536 K) - use a number of kilobytes.

	      An integer and M (e.g. 256 M) - use a number of megabytes.

	      An integer and G (e.g. 1 G) - use a number of gigabytes.

	      An integer and % (e.g. 50 %) - use a percentage of the amount of RAM.

	      You can optionally install the compcache package to configure this setting via debconf and have userspace scripts to load and unload
	      compcache.

NFS VARIABLES

	BOOT  Allows one to use an nfs drive as the root of the drive.	The default is to boot from local media (hard drive, USB stick).   Set	to
	      nfs for an NFS root share.

	DEVICE
	      Specifies the network interface, like eth0.

	ROOT  Allows optional root bootarg hardcoding, when no root bootarg can be passed.  A root bootarg overrides that special setting.

	NFSROOT
	      Defaults to auto in order to pick up value from DHCP server.  Otherwise you need to specify HOST:MOUNT.

FILES

       /etc/initramfs-tools/initramfs.conf

AUTHOR

       The  initramfs-tools  are  written  by  Maximilian Attems <maks@debian.org>, Jeff Bailey <jbailey@raspberryginger.com> and numerous others.
       Loosely based on mkinitrd.conf by Herbert Xu.

SEE ALSO

	initramfs-tools(8), mkinitramfs(8), update-initramfs(8).

Linux								    2010/11/22							 INITRAMFS.CONF(5)