initramfs.conf (5) - Linux Man Pages
initramfs.conf: configuration file for mkinitramfs
DESCRIPTIONThe 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.
- Specifies the modules for the initramfs image./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.
Modules listed in
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.
- Include busybox utilities for the boot scripts. If set to 'n' mkinitramfswill build an initramfs without busybox. Beware that many boot scripts need busybox utilities.
- Amount of RAM to use for RAM-based compressed swap space. The default is not to use compcache.65536 K) - use a number of kilobytes.
An empty value - compcache isn't used, or added to the initramfs at all.
An integer and K (e.g.
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.
- Specifies the compression method used for the initramfs image. mkinitramfswill default to gzip if the kernel lacks support (CONFIG_RD) or the corresponding userspace utility is not present.
- Set the umask value of the generated initramfs file. Useful to not disclose eventual keys.
- Allows one to use an nfs drive as the root of the drive. The default is to boot fromlocal media (hard drive, USB stick). Set to nfs for an NFS root share.
- 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%.
- Specifies the modules for the initramfs image.
VARIABLES FOR LOCAL BOOT
- 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 toauto, mkinitramfs will automatically select the largest available swap partition. Set it to none to disable resume from disk.
VARIABLES FOR NFS BOOT
- Specifies the default network interface to use, like eth0. Theip or BOOTIF bootargs may override this.
- Specifies the VLAN tag id to setup, e.g. VLAN=eth0.1:eth0. Thevlan bootarg may override this.
- Allows optional root bootarg hardcoding, when no root bootarg can be passed. A root bootarg overrides that special setting.
- Defaults toauto in order to pick up value from DHCP server. Otherwise you need to specify HOST:MOUNT.