Syslinux - Jun 2019 - Help! Extlinux no longer bootable after reorder disk numbers

I split one partition, then my hard drive partitions and my partition
numbers are listed in the wrong order and I fixed them
<https://journalxtra.com/linux/how-to-reorder-linux-drive-partition-numbers/>
so
they run sequentially from lowest to highest.

And the problem is, as the article
<https://journalxtra.com/linux/how-to-reorder-linux-drive-partition-numbers/>
has
warned, my disks are "completely buggered" and none of my existing
Ubuntu
systems can boot now. The Extlinux boot will complain something about:

requested disk number partition combination not found

If booting from Live CD, all the Ubuntu systems/partitions are still
mountable, no data have lost, but just none of them are bootable any more,
even after I reinstalled the extlinux boot to them (extlinux --install
/mnt/sdax/boot/extlinux), which is what I've been using before.

Now, details on how I boot my Ubuntu systems -- the active partition is a
Linux/Ubuntu system, that can still boot (from extlinux, because it resides
before the reordered partitions), and it in turn chain boots other Ubuntu
systems, with

  KERNEL chain.c32
  APPEND hd0 x

Judging from the extlinux above boot error message, it looks to me that the
chain boot is not working properly -- as if it still have an old copy of
the partitions' mapping, but this is only a wild guess.

my system:

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.1 LTS
Release:        18.04
Codename:       bionic

Is it still possible to get my Ubuntu systems booted?


Thanks a lot!

On Tue, Jun 25, 2019 at 12:32 AM Tong Sun <suntong001 at gmail.com> wrote:
> I split one partition, then my hard drive partitions and my partition
> numbers are listed in the wrong order and I fixed them
>
<https://journalxtra.com/linux/how-to-reorder-linux-drive-partition-numbers/>
so
> they run sequentially from lowest to highest.
>
> And the problem is, as the article
>
<https://journalxtra.com/linux/how-to-reorder-linux-drive-partition-numbers/>
has
> warned, my disks are "completely buggered" and none of my
existing Ubuntu
> systems can boot now. The Extlinux boot will complain something about:
>
> requested disk number partition combination not found
>
>
Took a screenshot and tracked down the exact place that output the error:
Logical partition (in EBR) with invalid offset and/or length

https://repo.or.cz/syslinux.git/blob/HEAD:/com32/chain/partiter.c#l189

So it seems that my extended boot record (EBR) has been structurally
damaged, slightly, that chain/partiter is complaining about it but mounting
it, is OK.

If booting from Live CD, all the Ubuntu systems/partitions are
still
> mountable, no data have lost, but just none of them are bootable any more,
> even after I reinstalled the extlinux boot to them (extlinux --install
> /mnt/sdax/boot/extlinux), which is what I've been using before.
>
> Now, details on how I boot my Ubuntu systems -- the active partition is a
> Linux/Ubuntu system, that can still boot (from extlinux, because it resides
> before the reordered partitions), and it in turn chain boots other Ubuntu
> systems, with
>
>   KERNEL chain.c32
>   APPEND hd0 x
>
> Judging from the extlinux above boot error message, it looks to me that
> the chain boot is not working properly -- as if it still have an old copy
> of the partitions' mapping, but this is only a wild guess.
>
> my system:
>
> $ lsb_release -a
> No LSB modules are available.
> Distributor ID: Ubuntu
> Description:    Ubuntu 18.04.1 LTS
> Release:        18.04
> Codename:       bionic
>
> Is it still possible to get my Ubuntu systems booted?
>
>
> Thanks a lot!
>
>
>