On Mon, Jun 29, 2020 at 11:44:40AM -0400, Hendrik Boom wrote: > On Tue, Jun 30, 2020 at 12:36:58AM +1000, terryc wrote: > > On Mon, 29 Jun 2020 08:18:24 -0400 > > Hendrik Boom <hend...@topoi.pooq.com> wrote: > > > > > > > Does it determine which MBRs to update by looking at the BIOS 'boot' > > > flags? > > > > As I understand it, the boxen looks at the UEFI(?) for the pointer to > > which piece of HW carries the initial loader, which then loads "grub" > > and its configuration files and the modules it needs to access the > > basic system to build up the OS to the final system. > > My hardware does not do UEFI. It is a BIOS system. > > Two of the drives are smallish, and have the old-style partitioning, > with four primary partitions, one of which is subdivided into secondary > partitions, One of these drives is the problem. > > I have two large EFI-partitioned disks, starting of course with
Correction. They are GPT-patitioned disks. EFI is a boot procedure which I don't use; GPT is a prartinioning scheme. I confused the two acronyms. > "protective MBR"s. These are working properly. > /boot is on these drives. Well, actually in one partition on each of > them, these partitions paired off as a software RAID. > > > > > The only file that I can find that points to any articular piece of > > hardware is /boot/grub/grub.cfg, which shoud list the various boot > > menu options. which points to hd0 with a device-id. > > Looked through that. It contains descriptions of all the operating > systems on my disk drives, identified by some kind of UUID. It does not > seem to have anything describing where boot from initially to load grub > stage 1 or grub stage 1.5. This is what I expected, because the > early stages of Grup already have to be loaded and running before it > can even understand the /boot file system. > Grub stage 1.5 presumably looks through the menu and figures out what > partition contains the /boot it si supposed to look for. > > > > > > Or is there some configuration file somewhere? > > > > So when (for me) sudo apt-get dist-upgrade loads newer images and runs > > grub-update/update-grub/?? is runs it probably checks what is in the > > existing grub.cfg and just adjust the various boot menu options(add > > newest, drops oldest). > > > > If you can get the machine to boot, there is a method to > > copy the grub config to a floppy or I guess a usb stick > > these days. > > Machine boots fine. Just won't upgrade. > > > > > At one stage, writing a spare boot floppy and keeping it up todate was > > recommended. > > I used to do that, but no loger have a floppy drive. I'd have to use a > USB stick, or perhaps even a Devuan installer used as a rescue disk. > > -- hendrik > > > > > Remember the reference to the hardware wll be 'primative' as t only has > > a basic system at first. > > _______________________________________________ > > Dng mailing list > > Dng@lists.dyne.org > > https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng > _______________________________________________ > Dng mailing list > Dng@lists.dyne.org > https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng _______________________________________________ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
