Jens Schmidt (12024-07-10): > On Debian testing I've been bitten by the systemd upgrade and the > systemd package split recently, rendering my dracut-LUKS-based > system unbootable. I know that my warranty is void since I'm on > testing, but both these issues would have been much easier to cope > with if there had been some good backup of my initramfs and kernel > below /boot. > > So I thought that there might be some automatism like this: > > If the currently used kernel and initramfs have been in use > already N times and if the boot time has been lower then M > minutes each time (and if some other conditions are fulfilled), > then consider that kernel and initramfs good and save them away > where they will not be overwritten by regular kernel/initramfs > maintenance. > > Scripting something like that shouldn't be too hard, but I wonder > if there already is a package implementing that? A cursory search > hasn't brought up anything. There is package dracut-config-rescue, > but that only configures a variable that does not seem to be used > by dracut itself.
I will say: this is probably not possible with Debian, since an apt-get (dist-)uupgrade replaces distributed files, and initrds are rebuilt, etc. You can consider using a LVM snapshot, but you can only make one reliably when the system is read-only. You can consider using a filesystem snapshot, but filesystems that support snapshots have their own set of problems. On the other hand, I can say it is a feature of NixOS, I saw it last week when somebody asked me “I made a mistake, our VM doesn't boot anymore, can I access the GRUB console?” and they just rebooted on the previous configuration. But NixOS is not Debian, it is barely Unix as far as I can see. Regards, -- Nicolas George
