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On 3/17/20 9:00 PM, John Covici wrote: |
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> On Tue, 17 Mar 2020 19:23:53 -0400, |
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> Dutch Ingraham wrote: |
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>> |
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>> On 3/17/20 4:16 AM, Neil Bothwick wrote: |
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>>> On Tue, 17 Mar 2020 03:00:59 -0500, Dutch Ingraham wrote: |
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>>> |
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>>>> Also from [1], with emphasis added "30_os-prober this script uses |
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>>>> **os-prober to search for Linux** and other operating systems and places |
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>>>> the results in the GRUB 2 menu. |
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>>>> |
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>>>> A review of the scripts 10_linux and 30_os-prober supplied by Gentoo |
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>>>> with the grub and os-prober packages seems to confirm the Ubuntu |
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>>>> documentation's accuracy. |
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>>>> |
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>>>> Regardless of which script is responsible, the problem remains that |
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>>>> running 'grub-mkconfig -o /boot/grub/grub.cfg' under the circumstances |
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>>>> outlined in my original post should find the other Linux operating |
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>>>> systems, but doesn't. |
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>>> |
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>>> You're right, either things have changed since the days I used GRUB |
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>>> extensively or I am losing it. No, that's not a multiple choice question! |
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>> |
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>> Well, you wouldn't be the first to begin losing it! I sent the original |
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>> question before running things through strace, so.... (It wasn't |
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>> particularly helpful.) |
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>>> |
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>>> Have you tried running the script with "sh -x" to see just what it is |
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>>> doing? |
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>> |
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>> It calls a helper script and exits successfully. |
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>> |
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>> I wonder if it could be this part |
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>>> |
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>>> if ! command -v os-prober > /dev/null || ! command -v linux-boot-prober >/dev/null ; then |
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>>> # missing os-prober and/or linux-boot-prober |
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>>> exit 0 |
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>>> fi |
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>> |
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>> Running `command -v os-prober' returns '/usr/bin/os-prober' |
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>>> |
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>>> If the os-prober command is missing the script will fail successfully, as |
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>>> you experience. Is sys-boot/os-prober installed? |
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>>> |
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>>> |
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>> Yes, it is installed as noted above, and, if I mount the partitions |
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>> manually, os-prober will find them. |
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>> |
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>> |
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>> I'm fairly certain I am missing one open and obvious thing, but can't |
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>> see it. Here is a list of things I have tried, mainly for |
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>> thread-completeness purposes: |
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>> |
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>> 1. Removed grub and op-prober packages then wiped all residual config files. |
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>> |
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>> 2. Reinstalled both, enabling the 'mount' use flag on grub. |
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>> |
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>> 3. Confirmed /usr/bin/os-prober and all /etc/grub.d/{scripts} are in |
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>> place and executable. |
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>> |
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>> 4. Even though it is the default, added GRUB_DISABLE_OS_PROBER=false to |
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>> /etc/default/grub. |
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>> |
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>> 5. Even though it is the default, set GRUB_PLATFORMS="pc" in make.conf. |
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>> |
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>> |
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>> On a fairly routine set-up (MBR/BIOS with four ext4 primary partitions) |
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>> I should be able to just set the mount use flag on grub, install grub |
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>> and os-prober, run 'grub-mkconfig -o /boot/grub/grub.cfg' and it should |
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>> just detect all operating systems and write the config, right? RIGHT? |
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>> |
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>> |
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> |
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> Are you sure its supposed to detect them even if they are not mounted? |
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> How would they be able to look at the files? Where are the image |
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> files on these partitions? |
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> |
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|
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Those are good questions. As far as I have seen, distributions act in |
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one of three different ways: |
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|
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1. Patch grub/os-prober in such a way that all operating systems |
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are detected rapidly, but not necessarily accurately. OpenSuSE works |
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this way, and can find 8 operating systems spread across two SSDs in |
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less than 10 seconds, albeit sometimes older kernels are listed as the |
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default for any given OS. No manual mounting of OSs is necessary. |
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|
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2. Patch grub/os-prober in such a way that all operating systems |
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are detected very slowly but accurately. The Debians/Ubuntus and Fedora |
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work this way, but take up to five minutes to complete on a two-SSD |
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system. No manual mounting of OSs is necessary. |
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|
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3. Vanilla grub/os-prober. Manual mounting of all OSs is required. |
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Arch Linux works this way. See |
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https://wiki.archlinux.org/index.php/GRUB#Detecting_other_operating_systems |
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. |
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I'm assuming 1 & 2 above are patched only anecdotally. There could be |
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something totally distinct happening. |
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The os-prober code itself, at least Gentoo's version, seems to indicate |
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it should find other OSs without manual mounting, as the code comments |
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and commands like lsblk, blkid, and mount would serve no other obvious |
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purpose. |
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Unfortunately I don't have the time right now to do a proper analysis of |
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the code from 1, 2, and 3 above against Gentoo's, so I suppose manually |
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mounting will have to suffice. |
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