Ubuntu Manpage: initramfs.conf - configuration file for mkinitramfs

Provided by: initramfs-tools-core_0.140ubuntu17_all

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/initramfs-tools/conf.d directory.  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 (CONFIG_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.

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.

RUNSIZE
The size of the /run tmpfs mount point in bytes (suffixes are supported) or as
percentage of your physical RAM. This parameter is used as the value of the size
mount option to tmpfs. See
https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt for details. Can be
overridden by an optional initramfs.runsize= bootarg. The default is 10%.

VARIABLES FOR LOCAL BOOT

        RESUME
              Specifies  the  device  used for suspend-to-disk (hibernation), which the initramfs
              code should attempt to resume from.  If this is not defined  or  is  set  to  auto,
              mkinitramfs will automatically select the largest available swap partition.  Set it
              to none to disable resume from disk.

        FSTYPE
              Specifies the filesystem type(s) to support, separated by commas.  If this  is  not
              defined  or  is set to auto, mkinitramfs will automatically detect the current root
              and /usr filesystem types.

VARIABLES FOR NFS BOOT

        DEVICE
              Specifies the default network interface to  use,  like  eth0.   The  ip  or  BOOTIF
              bootargs may override this.

        VLAN  Specifies  the  VLAN  tag id to setup, e.g. VLAN=eth0.1:eth0.  The vlan bootarg may
              override this.

        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.