Sorry for the delay. - /boot is ext4. - I have no idea how the image got corrupted. I have seen this only once.
>> AFAICT the new initrd.img is constructed on /boot, while >> the previous initrd is still in place. > > That is intentional and not a bug. I think I understood where the 3rd image is stored: In /var/tmp/\ initramfs.XXXXXXX. If /boot is not a dedicated partition, then disk space is shared between /var/tmp and /boot, increasing the risk for a full disk at update-initramfs runtime. Regards Harri
