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.TH INITRAMFS.CONF 5 "2010/11/22" "Linux" "initramfs.conf manual"
.SH NAME
initramfs.conf \- configuration file for mkinitramfs
.SH DESCRIPTION
The behaviour of
.B 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: \fIname\fP=[\fIvalue\fP]
Configuration options can be broken out into configuration snippets and
placed in individual files in the /etc/mkinitramfs/conf.d directory. Files
in this directory are always read \fBafter\fP the main configuration file,
so you can override the settings in the main config file without editing it
directly.
.SH GENERAL VARIABLES
.TP
\fB MODULES
Specifies the modules for the initramfs image.
Modules listed in \fI/etc/initramfs-tools/modules\fP and
\fI/usr/share/initramfs-tools/modules.d/*\fP are always included in the
initramfs, and are loaded early in the boot process.
\fIlist\fP doesn't load any additional modules at boot time, other than those
listed in the above files.
\fImost\fP adds most file system, all ata, sata, scsi and usb drivers.
\fIdep\fP tries to guess which modules are necessary for the running box and
only adds those modules.
\fInetboot\fP adds the base and network modules, but skips block devices.
The default setting is \fImost\fP.
.TP
\fB BUSYBOX
Include busybox utilities for the boot scripts.
If set to 'n'
.B mkinitramfs
will build an initramfs without busybox.
Beware that many boot scripts need busybox utilities.
.TP
\fB COMPRESS
Specifies the compression method used for the initramfs image.
.B mkinitramfs
will default to gzip if the kernel lacks support (CONFIG_RD) or the
corresponding userspace utility is not present.
.TP
\fB UMASK
Set the umask value of the generated initramfs file.
Useful to not disclose eventual keys.
.TP
\fB 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. \fI65536 K\fP) \- use a number of kilobytes.
An integer and M (e.g. \fI256 M\fP) \- use a number of megabytes.
An integer and G (e.g. \fI1 G\fP) \- use a number of gigabytes.
An integer and % (e.g. \fI50 %\fP) \- use a percentage of the amount of RAM.
You can optionally install the \fIcompcache\fP package to configure this
setting via debconf and have userspace scripts to load and unload compcache.
.SH NFS VARIABLES
.TP
\fB BOOT
Allows one to use an nfs drive as the root of the drive.
The default is to boot from \fIlocal\fP media (hard drive, USB stick).
Set to \fInfs\fP for an NFS root share.
.TP
\fB DEVICE
Specifies the network interface, like eth0.
.TP
\fB ROOT
Allows optional root bootarg hardcoding, when no root bootarg can be passed.
A root bootarg overrides that special setting.
.TP
\fB NFSROOT
Defaults to \fIauto\fP in order to pick up value from DHCP server.
Otherwise you need to specify \fIHOST:MOUNT\fP.
.SH FILES
.TP
.I /etc/initramfs-tools/initramfs.conf
.SH 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.
.SH SEE ALSO
.BR
.IR initramfs-tools (8),
.IR mkinitramfs (8),
.IR update-initramfs (8).
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