Re: Automatic creation of last-known-good boot configuration
Dan Ritter wrote:
> Jens Schmidt wrote:
>> 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.
>
> Are you using grub as your bootloader? Normally apt upgrade
> leaves the last N (N=5?) kernels and initramfs in /boot, and
> configures grub to make them available. apt dist-upgrade, on the
> other hand, tries to remove the oldest unused kernel and
> initramfs each time.
i do tell apt specifically to not remove any kernel images
by using the option NeverAutoRemove in apt.conf
=
APT
{
NeverAutoRemove { "linux-image.*"; }; // packages that should never
// considered for autoRemove
};
=
usually after each kernel upgrade i'll remove the third oldest one
leaving me the most current one and the one that i used previously
if it seems to have been stable enough. i like doing some things
manually and this is one of them. the other one i prefer to do
myself is bring up the network connection. sometimes i don't need
it so prefer to leave the connection off...
also, just out of a good idea i usually keep a stable booting
partition. this saves me at times.
songbird
Re: Automatic creation of last-known-good boot configuration
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
Re: Automatic creation of last-known-good boot configuration
Jens Schmidt wrote: > 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. Are you using grub as your bootloader? Normally apt upgrade leaves the last N (N=5?) kernels and initramfs in /boot, and configures grub to make them available. apt dist-upgrade, on the other hand, tries to remove the oldest unused kernel and initramfs each time. -dsr-
Re: Automatic creation of last-known-good boot configuration
On 2024-07-10, Jens Schmidt wrote: > 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. I compile my kernel adding a version suffixe. But the problem is the same if I compile a new version without a different suffixe. Perhaps a better way would be to save the "good" kernel in /boot with an additionnal suffixe. Then generate a grub entry for it (update-grub should does it). So you can directly boot with it. It supposes enough available space in /boot.
Automatic creation of last-known-good boot configuration
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. Please CC me when replying. Thanks!
