On 15.11.2022 21:13, David T-G wrote:
Andrei, et al --
...and then Andrei Borzenkov said... % On 05.11.2022 18:30, David T-G wrote: % > % > I've just gone back in again, and I see that. Of course, I am still VERY % > confused at how this % > % > davidtg@jpo:~> sudo parted /dev/sda p free % > Model: ATA SAMSUNG MZ7LN128 (scsi) % > Disk /dev/sda: 128GB % > Sector size (logical/physical): 512B/512B % > Partition Table: gpt % > Disk Flags: pmbr_boot % > Number Start End Size File system Name Flags % > 17.4kB 1049kB 1031kB Free Space % > 1 1049kB 35.4GB 35.4GB linux-swap(v1) jpo-swap swap % > 2 35.4GB 69.8GB 34.4GB xfs jposuse % > 3 69.8GB 104GB 34.4GB xfs jpoalt legacy_boot % > 4 104GB 128GB 23.9GB xfs jpo-ssd % > % > can boot, and nobody seems to have any answers, % % There is not enough information to provide any answer. All that is needed to
Sorry about that. I had posted content before, but I agree that I didn't post it this time.
% boot in this configuration is code in MBR that knows how to load next stage % code. Next stage code can be loaded from partition (unless you are using % some fancy bootloader that misuses post-MBR gap on GPT). Code in MBR could
Not as far as I know ... It's just grub2, and it's just a simple single-disk installation with only 1M free at the beginning of the disk.
% be grub2 or could be Syslinux gptmbr or something else. If you want the % definitive answer, you need to show bootinfoscript output.
=> Grub2 (v2.00) is installed in the MBR of /dev/sda and looks at sector 105657120 of the same hard drive for core.img. core.img is at this location and looks for (,gpt2)/boot/grub2. It also embeds following components: modules --------------------------------------------------------------------------- fshelp xfs part_gpt biosdisk --------------------------------------------------------------------------- Sector 105657120 is inside /dev/sda2 Partition Attrs Start Sector End Sector # of Sectors System /dev/sda1 2,048 69,208,063 69,206,016 Swap partition (Linux) /dev/sda2 69,208,064 136,316,927 67,108,864 Data partition (Linux) and /dev/sda2 seems to be your root partition Device Mount_Point Type Options ... /dev/sda2 / xfs (rw,relatime,attr2,inode64,logbufs=8,logbsize=32k,noquota) grub modules in core.img match it (grub needs gpt and xfs drivers to access root partition to read kernel etc). All of this explains how does it work.