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Hi, |
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OK, it's the day after Christmas and this little kid wants to play |
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with the new toys Uncle Neil gave us yesterday - a copy of his well |
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worn setup file for building an initramfs into the kernel - a copy of |
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which I place here: |
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|
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[QUOTE] |
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|
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This is the file I use on a system that has / on a LUKS filesystem on top |
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of LVM. The format is documented in the kernel docs at |
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Documentation/filesystems/ramfs-rootfs-initramfs.txt |
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|
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|
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dir /bin 755 0 0 |
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file /bin/busybox /bin/busybox 755 0 0 |
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slink /bin/sh busybox 777 0 0 |
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|
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dir /realroot 755 0 0 |
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dir /etc 755 0 0 |
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dir /proc 755 0 0 |
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dir /sys 755 0 0 |
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|
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dir /sbin 755 0 0 |
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file /sbin/lvm.static /sbin/lvm.static 755 0 0 |
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#file /sbin/mdadm /sbin/mdadm 755 0 0 |
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file /sbin/cryptsetup /sbin/cryptsetup 755 0 0 |
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|
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file /sbin/e2fsck /sbin/e2fsck 755 0 0 |
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dir /lib 755 0 0 |
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file /lib/libext2fs.so /usr/lib64/libext2fs.so 755 0 0 |
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|
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dir /dev 755 0 0 |
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nod /dev/console 600 0 0 c 5 1 |
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nod /dev/null 666 0 0 c 1 3 |
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nod /dev/tty 666 0 0 c 5 0 |
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nod /dev/urandom 666 0 0 c 1 9 |
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|
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file /init /usr/src/init.sh 755 0 0 |
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|
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[/QUOTE] |
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|
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|
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OK, so reading through this it seems moderately straight forward. My reading: |
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|
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a) Create some directories |
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b) Populate them with some executables |
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c) Make some nodes |
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d) Execute a script |
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|
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I do have a few questions: |
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|
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1) dir /realroot 755 0 0 |
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|
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Is this something required to make the machine boot? Or is it possibly |
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a mount point in case of problems and just used inside the initramfs |
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if trouble arises? Something else? Google didn't point me toward |
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anything meaningful. |
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|
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2) Contained executables, as I understand them, either need to be |
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built with the static flag or you have to include all the libraries. |
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Static seems simpler so (in my case) should I rebuild mdadm & |
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e2fsprogs with +static? (I don't currently use lvm or any crypt stuff) |
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I assume from the line |
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|
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file /lib/libext2fs.so /usr/lib64/libext2fs.so 755 0 0 |
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that running ldd on the new mdadm is still going to require this one |
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library be in the initramfs? |
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3) My system uses RAID today. Is there any significant risk in |
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rebuilding mdadm with static support, rebooting the existing kernel |
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without an initramfs and then mdadm having trouble? |
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|
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4) What's in /usr/src/init.sh ? From the Gentoo initramfs wiki I find |
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this as an example: |
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rescue_shell() { |
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echo "Something went wrong. Dropping you to a shell." |
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busybox --install -s |
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exec /bin/sh |
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} |
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I wonder what Uncle Neil uses? (Or anyone else...) |
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|
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Yipee!!! Better than the Red Ryder BB gun complete with a compass |
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and a sundial I was hoping for! ;-) |
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(And if it's not clear, I'm hoping this thread might possibly help |
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others in the future move from one place about initramfs to another |
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place about initramfs. We'll see.) |
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|
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Cheers, |
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Mark |
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