On 8/3/2020 11:18 AM, D. R. Evans wrote:
Tom Dial wrote on 8/1/20 9:31 PM:My experience, now on eight machines, indicates that it should be if the installed, configured, and used versions of grub components is 2.02+dfsg1-20+deb10u2. I could be wrong, but here it has been the case for both UEFI (and root on ZFS) and legacy boot setups, on both i386 and amd64. The only exception is one root-on-ZFS VM that was slightly broken beforehand and declines to boot for reasons I am fairly sure are unrelated to grub installation.So if one has two bootable drives (call them A and B), will this update update the MBR on both A and B, not just the one that happened to have been used for the most recent boot?
What update, specifically? With multiple boot targets, in general any updates to boot process must be updated on the individual targets separately. This is true of both UEFI and MBR boot processes.
I ask because I have a couple of root-on-ZFS BIOS-boot machines that are both configured as two-disk mirrors and I want to be sure that, following this upgrade, I can still boot off either of the two disks (as I can at the moment) without having to perform any manual changes.
You need to install GRUB on all of the mirrors, two in this case. Issue the commands `grub-install /dev/sda` and `grub-install /dev/sdb`, assuming the mirrors are /dev/sda and /dev/sdb.
I am given to understand the ZFS pools will also need to be duplicated.