を使用して作成されたかなり標準的な初期RAMディスクがありますmkinitcpio。私はArch GNU / Linuxを使用しています。
しばらく前に、リカバリシェルに投げられ、/bin仮想ディスクを見回して何が利用可能かを調べました。何らかの理由で重要ではないユーティリティがたくさんあります（このようなことを考えてください。ping構造環境でなぜこれを使用したいのですか？）。
alex@alexs-arch-imac:/tmp$ mkdir initramfs
alex@alexs-arch-imac:/tmp$ cd initramfs
alex@alexs-arch-imac:/tmp/initramfs$ cp /boot/initramfs-linux.img .
alex@alexs-arch-imac:/tmp/initramfs$ cat initramfs-linux.img | unlzma - >
initramfs-linux # needed because unlzma complains that it doesn't recognize the .img extension
alex@alexs-arch-imac:/tmp/initramfs$ cpio -iV < initramfs-linux
.............................................................................................................................................................................................................................................................................................................................................................
24225 blocks
alex@alexs-arch-imac:/tmp/initramfs$ ls
bin buildconfig config dev etc hooks init init_functions initramfs-linux initramfs-linux.img lib lib64 new_root proc run sbin shutdown sys tmp usr VERSION
alex@alexs-arch-imac:/tmp/initramfs$ ls -l bin
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 bin -> usr/bin
alex@alexs-arch-imac:/tmp/initramfs$ ls bin
[ blkid chown cttyhack dirname egrep free hexdump ip iptunnel less ls mkfifo mount nslookup ping6 readlink route sha1sum stat tac touch uniq yes
[[ busybox chroot cut dmesg env getopt ifconfig ipaddr kbd_mode ln lsblk mknod mountpoint openvt poweroff reboot sed sha256sum strings tail true uptime
ash cat clear dd dmsetup expr grep init iplink kill loadfont lsmod mktemp mv pgrep printf rm seq sha512sum switch_root telnet udevadm vi
awk chgrp cp depmod du false halt insmod iproute killall loadkmap md5sum modinfo nc pidof ps rmdir setfont sleep sync test umount wc
basename chmod cryptsetup df echo findmnt head install iprule kmod losetup mkdir modprobe netstat ping pwd rmmod sh sort systemd-tmpfiles tftp uname wget
alex@alexs-arch-imac:/tmp/initramfs$
この画像に最も奇妙な便利です。見るだけでも理解できますが、、、wget…これはなぜここにいますか？pingtelnetsha1sum
これが私の結果です/etc/mkinitcpio.conf。画像はを使用して作成されましたmkinitcpio -p linux。
# vim:set ft=sh
# MODULES
# The following modules are loaded before any boot hooks are
# run. Advanced users may wish to specify all system modules
# in this array. For instance:
# MODULES="piix ide_disk reiserfs"
MODULES=""
# BINARIES
# This setting includes any additional binaries a given user may
# wish into the CPIO image. This is run last, so it may be used to
# override the actual binaries included by a given hook
# BINARIES are dependency parsed, so you may safely ignore libraries
BINARIES=""
# FILES
# This setting is similar to BINARIES above, however, files are added
# as-is and are not parsed in any way. This is useful for config files.
FILES=""
# HOOKS
# This is the most important setting in this file. The HOOKS control the
# modules and scripts added to the image, and what happens at boot time.
# Order is important, and it is recommended that you do not change the
# order in which HOOKS are added. Run 'mkinitcpio -H <hook name>' for
# help on a given hook.
# 'base' is _required_ unless you know precisely what you are doing.
# 'udev' is _required_ in order to automatically load modules
# 'filesystems' is _required_ unless you specify your fs modules in MODULES
# Examples:
## This setup specifies all modules in the MODULES setting above.
## No raid, lvm2, or encrypted root is needed.
# HOOKS="base"
#
## This setup will autodetect all modules for your system and should
## work as a sane default
# HOOKS="base udev autodetect block filesystems"
#
## This setup will generate a 'full' image which supports most systems.
## No autodetection is done.
# HOOKS="base udev block filesystems"
#
## This setup assembles a pata mdadm array with an encrypted root FS.
## Note: See 'mkinitcpio -H mdadm' for more information on raid devices.
# HOOKS="base udev block mdadm encrypt filesystems"
#
## This setup loads an lvm2 volume group on a usb device.
# HOOKS="base udev block lvm2 filesystems"
#
## NOTE: If you have /usr on a separate partition, you MUST include the
# usr, fsck and shutdown hooks.
HOOKS="base udev autodetect modconf keyboard block encrypt resume filesystems fsck shutdown"
# COMPRESSION
# Use this to compress the initramfs image. By default, gzip compression
# is used. Use 'cat' to create an uncompressed image.
#COMPRESSION="gzip"
#COMPRESSION="bzip2"
COMPRESSION="lzma"
#COMPRESSION="xz"
#COMPRESSION="lzop"
#COMPRESSION="lz4"
# COMPRESSION_OPTIONS
# Additional options for the compressor
#COMPRESSION_OPTIONS=""
ベストアンサー1
初期のRAMディスクはBusyboxを使用してスペースを節約します。基本的にmv同様のユーティリティは、cpファイル記述子を開く、メモリにバッファを読み込むなど、多くの共通ロジックを共有します。 Busyboxはデフォルトですべての一般的なロジックを名前に基づいて動作方法を変更するバイナリに入れます。 RAMディスクを見てみましょう。
alex@alexs-arch-imac:/tmp/initramfs/bin$ ls -l
total 1308
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 [ -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 [[ -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ash -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 awk -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 basename -> busybox
-rwxr-xr-x 1 alex alex 68840 Mar 24 17:06 blkid
-rwxr-xr-x 1 alex alex 287096 Mar 24 17:06 busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 cat -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 chgrp -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 chmod -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 chown -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 chroot -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 clear -> busybox
-rwxr-xr-x 1 alex alex 130272 Mar 24 17:06 cp
-rwxr-xr-x 1 alex alex 59264 Mar 24 17:06 cryptsetup
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 cttyhack -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 cut -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 dd -> busybox
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 depmod -> kmod
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 df -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 dirname -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 dmesg -> busybox
-r-xr-xr-x 1 alex alex 92227 Mar 24 17:06 dmsetup
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 du -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 echo -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 egrep -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 env -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 expr -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 false -> busybox
-rwxr-xr-x 1 alex alex 53696 Mar 24 17:06 findmnt
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 free -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 getopt -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 grep -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 halt -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 head -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 hexdump -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ifconfig -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 init -> busybox
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 insmod -> kmod
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 install -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ip -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ipaddr -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 iplink -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 iproute -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 iprule -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 iptunnel -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 kbd_mode -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 kill -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 killall -> busybox
-rwxr-xr-x 1 alex alex 142424 Mar 24 17:06 kmod
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 less -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ln -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 loadfont -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 loadkmap -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 losetup -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ls -> busybox
-rwxr-xr-x 1 alex alex 70192 Mar 24 17:06 lsblk
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 lsmod -> kmod
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 md5sum -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 mkdir -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 mkfifo -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 mknod -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 mktemp -> busybox
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 modinfo -> kmod
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 modprobe -> kmod
-rwsr-xr-x 1 alex alex 40168 Mar 24 17:06 mount
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 mountpoint -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 mv -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 nc -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 netstat -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 nslookup -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 openvt -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 pgrep -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 pidof -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ping -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ping6 -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 poweroff -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 printf -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 ps -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 pwd -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 readlink -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 reboot -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 rm -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 rmdir -> busybox
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 rmmod -> kmod
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 route -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sed -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 seq -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 setfont -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sh -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sha1sum -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sha256sum -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sha512sum -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sleep -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sort -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 stat -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 strings -> busybox
-rwxr-xr-x 1 alex alex 14816 Mar 24 17:06 switch_root
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 sync -> busybox
-rwxr-xr-x 1 alex alex 63992 Mar 24 17:06 systemd-tmpfiles
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 tac -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 tail -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 telnet -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 test -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 tftp -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 touch -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 true -> busybox
-rwxr-xr-x 1 alex alex 264696 Mar 24 17:06 udevadm
-rwsr-xr-x 1 alex alex 27616 Mar 24 17:06 umount
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 uname -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 uniq -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 uptime -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 vi -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 wc -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 wget -> busybox
lrwxrwxrwx 1 alex alex 7 Mar 24 17:06 yes -> busybox
alex@alexs-arch-imac:/tmp/initramfs/bin$
ご覧のとおり、この画像のほぼすべてのバイナリはBusyboxに接続されています。
alex@alexs-arch-imac:/tmp/initramfs/bin$ ls -l | grep --invert-match busybox -
total 1308
-rwxr-xr-x 1 alex alex 68840 Mar 24 17:06 blkid
-rwxr-xr-x 1 alex alex 130272 Mar 24 17:06 cp
-rwxr-xr-x 1 alex alex 59264 Mar 24 17:06 cryptsetup
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 depmod -> kmod
-r-xr-xr-x 1 alex alex 92227 Mar 24 17:06 dmsetup
-rwxr-xr-x 1 alex alex 53696 Mar 24 17:06 findmnt
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 insmod -> kmod
-rwxr-xr-x 1 alex alex 142424 Mar 24 17:06 kmod
-rwxr-xr-x 1 alex alex 70192 Mar 24 17:06 lsblk
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 lsmod -> kmod
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 modinfo -> kmod
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 modprobe -> kmod
-rwsr-xr-x 1 alex alex 40168 Mar 24 17:06 mount
lrwxrwxrwx 1 alex alex 4 Mar 24 17:06 rmmod -> kmod
-rwxr-xr-x 1 alex alex 14816 Mar 24 17:06 switch_root
-rwxr-xr-x 1 alex alex 63992 Mar 24 17:06 systemd-tmpfiles
-rwxr-xr-x 1 alex alex 264696 Mar 24 17:06 udevadm
-rwsr-xr-x 1 alex alex 27616 Mar 24 17:06 umount
alex@alexs-arch-imac:/tmp/initramfs/bin$ ls | wc -l # total number of files
116
alex@alexs-arch-imac:/tmp/initramfs/bin$ ls -l | grep --invert-match busybox - | grep --invert-match kmod | wc -l # number of real binaries minus two (busybox and kmod)
12
画像には116個のファイルがありますが、そのうち14個だけが実際にバイナリです。残りはすべてkmodからまたはへのシンボリックリンクですbusybox。
したがって、ランダムなユーティリティがあまりにも多くの理由は、そこに置く方が良いからです。シンボリックリンクはスペースを占有せず、削除してもBusyboxバイナリに機能が残ってスペースを占有します。すべてのリンクを削除する理由はほとんどないため、パッケージ作成者はこれを行いません。
考慮すべきもう一つの質問は次のとおりです。単にBusyboxバイナリからネットワーキング機能を削除するのはどうですか？ @Gillesが述べたようにはい正当な場合（まれに）initcpioでネットワークを設定する必要があります。したがって、パッケージャには2つのオプションがあります。現在行っていることを行い、基本的にすべてを含めるか、ネットワーク機能を独自のmkinitcpioフックに分割します。前者は非常に簡単で（基本的には何もしません）、費用はかなり少なくなりますが、2番目は非常に複雑であり（これを指摘してくれた@Gillesにもう一度感謝します）、利点はそれほど大きくありません。したがって、パッケージャは賢明なアプローチをとり、ネットワークに何の措置も取らなかった。