Following up on Install Grub2 to PBR, and opening a new question to provide link to boot-info-summary, as per @mook765:
Here is again the problem:
% grub-install /dev/sdc5
Installing for i386-pc platform.
grub-install: warning: File system `ext2' doesn't support embedding.
grub-install: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
grub-install: error: will not proceed with blocklists
grub-install refuses to proceed with blocklists, saying "File system 'ext2' doesn't support embedding". However, mine is not an
ext2 file-system but
ext4, and it does NOT need fsck:
$ mount | grep /dev/sdc5
/dev/sdc5 on /mnt/osp type ext4 (rw,noatime,nodiratime,data=ordered)
% umount /dev/sdc5
umount: /dev/sdc5: not mounted.
% fsck.ext4 /dev/sdc5
e2fsck 1.44.1 (24-Mar-2018)
osp: clean, 115049/513072 files, 897251/2048287 blocks
and for your convenient, here is the relevant part from the boot-info-summary:
File system: ext4
Boot sector type: Grub2 (v1.99-2.00)
Boot sector info: Grub2 (v1.99-2.00) is installed in the boot sector of
sdc5 and looks at sector 34172346 of the same hard
drive for core.img, but core.img can not be found at
Operating System: Ubuntu 18.04.2 LTS
Boot files: /boot/grub/grub.cfg /etc/fstab
Alright, let me explain my configuration a bit.
- I don't use
liloto boot my system. The only reason I put
liloin mbr is that, it has the advantage of being able to boot directly from extended partition, instead of from prime partitions only.
- Yes I have 4 MBRs, i.e., 4 HDs, but all HD are setup the same -- it will be booted from the active partition, show as "
fdisk -loutput, thanks to the lilo in mbr. In fact any normal MBR will do as all my active partition are prime partitions, not extended partition. But I just kept my option open.
- The active partition, of any HD, is booted by
extlinux. From there I chainload whatever I want to boot, from its boot menu.
- The normal Linux partition are booted by
extlinuxas well, but somehow I wasn't able to make
extlinux, so I switched to
grub2, and it had been booting fine before.
- The problem started when I try to make a USB partition bootalble, the "install the grub2 as the boot-loader from OS in partition-B to OS on partition-A" thing in my previous question.
- Now neither partition-B nor partition-A are bootable any more.
- For full disclosure, both partition-B and partition-A are restored from a LUbuntu system that I carefully installed and trimmed. This "restored" is the main reason I wasn't able to make it bootable via
extlinux, I suspect, but can't prove.
- Legacy grub is a staled partition/OS that I have't touch for years, even 10+ years, however,
- the grub4dos is the one I newly setup on my USB disk. It is bootable, and it allows me to chain boot into anything that I want, with simple syntax that I understand well. I.e., it has nothing to do with how my current system boot, as I may detach it at any moment.