On Fri 07 Apr 2017 12:02:46 +0200, intrigeri wrote:
> /lib/systemd/system/initramfs-shutdown.service:
> ⋯
> /usr/share/initramfs-tools/initramfs-restore:
> ⋯
> /usr/bin/unmkinitramfs /initrd.img "$WORKDIR"
> ⋯
> /lib/systemd/system-shutdown/initramfs-tools:
> ⋯
> /usr/share/initramfs-tools/hooks/shutdown:
> ⋯
> copy_exec /lib/systemd/systemd-shutdown /shutdown
> touch $DESTDIR/etc/initrd-release
I am interested in this ticket for two use cases:
a. netbooting Debian Live on diskless hosts.
b. "zpool export -a" on servers.
I am only considering case (a), below.
I tried intrigeri's approach for Debian Live but I ran into a couple of problems:
1. it assumes /initrd.img inside the rootfs exists and
is consistent with the already-running system.
This is not the case for me (I remove it to save space), and
also not necessarily the case during upgrades.
2. it tries to unpack /initrd.img after systemd-networkd stops.
Without KeepConfiguration= (which is a pain to guarantee),
that means no network access, which means no access to remote rootfs.
I instead tried just keeping the boot initrd around.
Using a simple bind-mount didn't work (I don't understand why) – SOME files are missing after switch_root.
Doing a full cp -a did work, though.
This method seems to work for my very simple test case of failed-to-unmount-rootfs error going away.
I'm really not happy with it overall, though.
I've run out of "time budget" to work on this in the short term.
https://github.com/cyberitsolutions/bootstrap2020/tree/twb/doc/workaround-778849
PS: I looked at dracut, but it's simply unsupported for live-boot (Debian Live / Tails), and
for servers, I found it unreliable (much worse than initramfs-tools).
(e.g. if bash has a security update, dracut doesn't trigger and the embedded copy of bash in the initrd remains vulnerable.)
(e.g. telling dracut to use only busybox/klibc and not bash breaks, because lots of dracut components need bash but don't declare a dependency on it.)
(e.g. dracut is written in bash and regularly has errors but doesn't exit non-zero, so you do not notice until the server doesn't actually boot anymore.)
Attachment:
usr_share_initramfs-tools_hooks_PrisonPC-install-systemd-shutdown
Description: Bourne shell script
Attachment:
shSmnrEZrhXc.sh
Description: Bourne shell script