MKINITRD(8)                                                        User Manuals                                                        MKINITRD(8)

NAME

       mkinitrd - create initrd disk image

SYNOPSIS

       mkinitrd [options] [root_dir]

DESCRIPTION

       mkinitrd creates initial ramdisk images for booting Linux. The "/init" script in the compressed cpio archive loads all driver modules,
       creates all device nodes currently known by the kernel, initializes vital subsystems (e.g. networking when doing nfs), does a filesystem
       check on the root filesystem and finally passes control to /sbin/init. udev is used to create the device nodes in a tmpfs mounted /dev
       directory. This directory is moved over to the final root filesystem, essentially hiding the on-disk content below /dev on the root
       filesystem.

       A few options can be specified via the kernel command line to modify some hardcoded values in the "/init" script. They are read from
       /proc/cmdline.

       While in the old days the Linux kernel was responsible for mounting the rootfilesystem and running /sbin/init, all the work is now done by
       the "/init" script.

OPTIONS

       -h
           Shows help output and exits.

       -R
           Prints the version and exits. We use -R (release) because -v (verbose) and -V (vendor scripts) are already taken.

       -k kernel_list
           List of kernel images for which initrd files are created (relative to boot_dir), defaults to vmlinux on ppc/ppc64, image on s390/s390x
           and vmlinuz for everything else.

       -i initrd_list
           List of file names (relative to boot_dir) for the initrd; positions have to match the kernel_list, defaults to initrd.

       -m module_list
           Modules to include in initrd, defaults to INITRD_MODULES variable in /etc/sysconfig/kernel.

       -f feature_list
           Features to be enabled for the initrd. In general mkinitrd configures the initrd for the root device it is started from. With this
           option additional feature can be enabled.

       -b bootdir
           Boot directory, defaults to /boot, where the initrd is created.

       -d root_device
           Root device, defaults to the device from which the root_dir is mounted; overwrites the rootdev enviroment variable if set

       -s size
           Add splash animation and bootscreen to initrd.

       -D interface
           Run dhcp on the specified interface (for example "eth0").

           It's also possible to specify "default" here if the default interface should be used. If there's a file /etc/install.inf (which is from
           the installation system), then the interface that was used for installation is used as default interface. Otherwise, if NFS root is
           used and one of the network configuration files in /etc/sysconfig/network contain the option STARTMODE=nfsroot, than this interface is
           used as default. Finally, the interface which is used for the default route (in the output of /sbin/route is used as default interface
           in the initrd.

       -I interface
           Configure the specified interface statically.

       -a acpi_dsdt
           Attach compiled ACPI DSDT (Differentiated System Description Table) to initrd. This replaces the DSDT of the BIOS. Defaults to the
           ACPI_DSDT variable in /etc/sysconfig/kernel.

       -e
           Use static binaries where possible. (currently unavailable)

       -P
           Include modules for all IDE devices on the PCI bus.

       -V script
           Vendor specific script to run in linuxrc.

       -M map
           System.map file to use.

       -j device
           External journal device to use for the root filesystem.

       -l directory
           Directory to use for mkinitrd files instead of /lib/mkinitrd.

       -B
           Don't run the update-bootloader(8) script after the initrd(s) have been created. This is useful if you call mkinitrd(8) not for the
           running system but for example in a spec file to pre-generate an initrd or to generate a special kdump initrd (which mkdumprd(8) does).

       -A
           Create a so called "monster initrd" which includes all available features and modules.

       -S
           Do not include all libata modules by default.

       -v
           Verbose mode. Prints more information to standard error. By default the information that would be printed in verbose mode is also
           appended to the log file /var/log/YaST2/mkinitrd.log, so it's not necessary to re-run mkinitrd with the -v option to create bug
           reports.

       -L
           Disable logging to /var/log/YaST2/mkinitrd.log. This is useful for testing if you don't want to clutter the system log.

       root_dir
           The directory the root partition is mounted to defaults to "/".

KERNEL COMMAND-LINE PARAMETERS
       mkinitrd implements a set of additional kernel command-line parameters which are interpreted by the generated init script. In addition to
       the standard kernel parameters the following parameters are supported:

       linuxrc=trace
           Enabling command tracing of the init script

       shell=1
           Execute a shell after the linuxrc has finished and before the normal system is booted. Useful for debugging.

       noresume
           Do not check for a resume device

       sysrq=yes | sysrq=1-9
           Enable sysrq. If a numeric value is specified, the log level of the console will be set to that value.

       *resume=*device
           Resume from device device.

       *journal=*device
           Use device device as external journal device. This is only valid for reiser and xfs filesystems.

       *mduuid=*UUID
           Mount md RAID with uuid UUID as the root filesystem.

       TargetAddress=IP_Address
           [iSCSI] IP Address of the iSCSI Target

       InitiatorName=iqn. [iSCSI] Use iqn as the iSCIS initiatorname.

       *ip=*ipspec
           Use ipspec to configure the network interface. Format of the ipspec is client:server:gateway:netmask:hostname:device:proto.  client,
           server, gateway, netmask are in the standard dotted-decimal IP notation.  proto is currently ignored.

       *udev_timeout=*secs
           Set the timeout for root device detection to secs seconds. Default is 10.

FEATURES

       Normally mkinitrd detects all required features automatically, based upon the current root, resume, dump and journal device. If additional
       features should be enabled, the -f option can be specified. Of course you can write your own features as well. Just take a look at
       /lib/mkinitrd.

       Currently, the following features can be selected (if a feature is available depends on the installed packages):

       block
           Include support for block devices (SCSI and IDE)

       busybox
           Replace and add all tools known as safe with the busybox versions

       dasd
           Include support for dasd storage devices (s390)

       dmraid
           Include support for Software-Raid over device mapper (known as Fake-Raid)

       dm
           Include support for device mapper in general

       firewire
           Include firewire storage

       ifup
           Include all network devices configured via ifup. The user should ensure to set the STARTMODE to onboot in the corresponding ifcfg
           files.

       iscsi
           Include iSCSI support

       kpartx
           Include support for kpartx partitioning. Always use this if you have device mapper devices.

       luks
           Include encryption support using luks

       lvm2
           Include support for LVM2

       md
           Include support for Software RAID (md)

       multipath
           Include support for multipathing

       netconsole
           Include support for debugging using netconsole

       network
           Include networking support

       nfs
           Include support for nfs(-root)

       resume.kernel
           Include resume support using the kernel resume code

       resume.userspace
           Include resume support using the userspace program

       usb
           Include USB-support (keyboard and storage)

       vendor
           Include vendor script support

       zfcp
           Include support for zfcp storage devices (s390)

USING NFS AS ROOT FILESYSTEM

       To configure an initrd for an NFS client, specify these options to add nfs and network driver support into the initrd:

       mkinitrd -f nfs -D eth0
           This will add the required kernel modules and a dhcp client to the initrd, which will try to get an IP address via eth0. Boot the NFS
           client with these additional command line options to mount the server: nfsroot=1.2.3.4:/exported/directory.

       mkinitrd -f nfs -I eth0
           This will add the required kernel modules to the initrd, a static IP address must be specified on the kernel cmdline. Boot the NFS
           client with the nfsroot parameter as specified above to mount the server and the additional parameter
           ip=1.2.3.42:1.2.3.4:1.2.3.1:255.255.255.0:hostname:eth0:none to configure the network interface. See the ip= description above for
           details about the ip= option.

       mkinitrd
           Due to the new autodetection in mkinitrd it should suffice if the /-entry in /etc/fstab is an nfs target. The network device which will
           be used should have STARTMODE set to nfsroot.

RECOVERY

       What should you do if the initrd is broken and you want to fix it using a chroot? I assume /mnt is your target root and /boot is mounted
       inside.

        1. mount --bind /dev /mnt/dev

        2. chroot /mnt

        3. mount /proc

        4. mount /sys

        5. mkinitrd

FILES

       /var/log/YaST2/mkinitrd.log
           The log file of this program. Always attach that log file in Bugzilla if something goes wrong. It's also included in the usual YaST
           logs that are created with save_y2logs(8).

ENVIRONMENT VARIABLES

       You can specify the root device via the environment variable rootdev (e.g. "rootdev=/dev/hda mkinitrd").

       Also, the temporary directory which is used to build the initrd can be specified using the TMPDIR environment. If not set, /dev/shm is used
       as root (when it's writable) and /tmp otherwise.

AUTHORS

       Steffen Winterfeldt <snwint@suse.de>, Susanne Oberhauser <froh@suse.de>, Andreas Grunbacher <agruen@suse.de>, Hannes Reinecke
       <hare@suse.de>, Alexander Graf <agraf@suse.de>, Bernhard Walle <bwalle@suse.de>

SEE ALSO

       mkinitrd(8), mkinitrd(5)

mkinitrd                                                            07/05/2010                                                         MKINITRD(8)