I'm having trouble booting a previously bootable system.
This system has been in use since very shortly before the Stretch release and has always been Stretch.
I'm using Grub to boot a fully encrypted system. Each drive is partitioned with GPT and encrypted using LUKS. The drives are then used together with BTRFS.
This system has worked with some minor boot problems (Which I thought were fixed by adding the bios_grub flag to my partition and the pmbr_boot flag to my disk) for at least a year.
Today I can not boot the system. I suspect I've made it worse for trying to repair it so I will jump to where I am now.
When I boot I get on either device:
error: no such device: (UUID of my decrypted luks volume / btrfs pool)
error: unknown filesystem
I've chrooted onto the system using a usb key.
I can open my encrypted drives and mount the btrfs filesystem.
I suspected a bad kernel or grub update so I:
update initramfs -u -k all
This gives the above errors when I boot.
When I inspected /boot/grub/grub.cfg I noted it is missing "insmod cryptodisk" and other encryption related modules. This is despite /etc/default/grub containing "GRUB_ENABLE_CRYPTODISK=y". I tried restoring /boot/grub/grub.cfg from a snapshot that does include those modules and then grub-install to both drives again but to no avail.
I'm really at a loss and could really use some help in restoring my system.