Comparison of the various replacements for initrd-tools

Architectures

initramfs-tools

yaird

amd64

(./) Works (?JeffBailey)

(./) Works (MarcoAmadori)

arm

<!> Needs Test

<!> Needs Test

alpha

<!> Needs Test

<!> Needs Test

hppa

{X} segfault in run_init (?JeffBailey)

<!> Needs Test

i386

(./) Works (Jeff Bailey)

(./) Works (JonasSmedegaard)

ia64

{X} inflate code misreads magic number (?JeffBailey)

{X} Also fails, probably for the same reason (DannFrazier)

m68k

{X} no klibc (not yet ported)

<!> Needs Test

mips

{X} no klibc (linux-header missing)

<!> Needs Test

mipsel

{X} no klibc (linux-header missing)

<!> Needs Test

powerpc

(./) Works (DannFrazier?)

(./) Works (?SvenLuther)

s390

{X} no klibc (untested?)

<!> Needs Test

sh

{X} no klibc (unstested?)

<!> Needs Test

sparc

(./) Works (?JeffBailey)

(./) Works (JurijSmakov)

Root Devices

initramfs-tools

yaird

fstab label and UUID

<!> Unknown

<!> Works but yuckilly. Needs to be rewritten to blkid, there are good ideas in http://bootutils.sourceforge.net/ -- ErikKonijnenburg

md

(./) Works (maximilianattems)

(./) Works (JonasSmedegaard)

LVM

(./) Works (maximilianattems)

(./) Works (MarcoAmadori)

LVM-over-md

<!> Needs Test

(./) Works (MarcoAmadori)

EVMS

<!> Works (Sesse)

<!> In progress see BTS #335230

EVMS-over-lvm

<!> Needs Test.

<!> Unknown

EVMS-over-md

<!> Needs Test, probably some modules to add.

<!> Unknown

EVMS-over-md-lvm

<!> Missing modules, add raid1, raid5,.. to /etc/mkinitramfs/modules.

<!> Unknown

Crypsetup

<!> Needs Test

(./) Works (?ManojSrivasta)

Crypsetup-luks?FootNote(cryptsetup-luks is not packaged officially for Debian)

<!> Unknown

<!> Tested round 0.0.8 (ErikKonijnenburg)

loopaes

<!> Unknown

{X} No

NFS

<!> Needs Test

<!> Requires manual editing config file (JonasSmedegaard)

SCSI

<!> Unknown

<!> Needs test

SATA

<!> Needs Test

(./) Works (MarcoAmadori)

USB-stick

<!> Needs Test

<!> Needs Test

IEEE1394

<!> Needs Test

{X} No

Compaq Smart Arrays

<!> Unknown

<!> Needs test

dmraid

<!> Unknown

{X} No

Other features

initramfs-tools

yaird

cramfs initrd

{X} No.

{X} Removed in 0.0.12 -- any reason to put it back? (ErikKonijnenburg)

USB keyboard

<!> Unknown

(./) Works (ErikKonijnenburg)

swsusp

<!> Needs Test

{X} No

swsusp2 ?FootNote(swsusp2 is not in mainline kernel)

<!> Unknown

<!> Requires manual editing config file, but so far I've seen two notes from people who got swsusp2 running with yaird, vs nobody for swsusp plain. This seems like a good one for me to work on (ErikKonijnenburg)

External hooks

(./) Yes

<!> requires manual editing config file

Package requirements (risk of delays on some archs)

initramfs-tools

yaird

klibc

<!> Yes

(./) No

busybox

<!> Yes

(./) No

udev

<!> Yes

(./) No

mklibs-copy?FootNote(mklibs-copy package dependency pulls in python2.4-minimal)

<!> Yes

(./) No

Arch: any

(./) No

<!> Yes (includes a few tiny C-based helper tools)

Runtime requirements

initramfs-tools

yaird

sysfs?FootNote(sysfs required at runtime limits to installing only '''from''' 2.6.8 and newer - specifically making upgrades directly from Linux 2.4.x to Linux 2.6.x impossible)

(./) No

<!> Yes

Boot-time requirements

initramfs-tools

yaird

udev?FootNote(udev required at boot-time limits to installing only Linux 2.6.12 and newer)

<!> Yes

(./) No

Legend

(./)

Great

<!>

Not great

{X}

Bad

Recent Linux kernels query the ramdisk tool prior to use if it is expected to succeed. Currently the following simplified queries try to handle all of the above contraints (see ?FlexibleKernelHandling for a future more finegrained approach):

kernel-package query

initramfs-tools

yaird

Supported host version

any

>=2.6.8

Supported target version

>=2.6.12

>=2.6.8

The main goal of all initrd tools is off course to generate an initial ramdisk to help boot a kernel properly. But beyond that, the tools have fundamental differences in their approach:

howto compose images

Builds generic image with plenty of included modules, and probes at boot time what to load

Builds specific image probing/resolving with sysfs at build time the modules to include and load at boot time

Ramdisk size

Relatively large by default- option of relatively small (with larger risk of failing)

quite small

Dealing with devices

Activates (it seems) all possible md and/or LVM volumes

Activates only md and/or LVM volume needed for mounting rootfs

Dealing with errors

If unsure then creates a larger more safe image

Fails to build image if uncertain it will work

libc used

Both klibc and (externally pulled in) glibc

glibc (can be compiled against klibc if needed)

Hilites not directly comparable

initramfs-tools

yaird