[gentoo-user] Re: How to move ext4 partition

[Grant Edwards <grant.b.edwards@gmail.com>]

On 2023-09-21, Victor Ivanov <vic.m.ivanov@gmail.com> wrote:
> On Wed, 20 Sept 2023 at 23:58, Grant Edwards <grant.b.edwards@gmail.com> wrote:
>
>>> Just make sure you update /etc/fstab and bootloader config file
>>> with the new filesystem UUID or partition indices.
>>
>> I always forget one or the other until after I try to boot the
>> first time.  That's why I keep systemrescuecd and Gentoo minimal
>> install USB drives on hand.
>
> Me too, even just recently when I migrated my OS to another build I
> decided to do a few partition touch ups and fell once more into this
> trap. I updated fstab but not the bootloader. Luckily, Gentoo
> minimal install image is so tiny a bootable medium can literally be
> created in minutes.

The tar backup restore worked just fine (and didn't take long, even
though both drives were connected via USB).  I've since fixed a second
machine by adding a bios-boot partition. I should have started using
them when I switched from MBR to GPT, but I think I got bios-boot
partitions confused with UEFI boot partitions. :/

I'm also working on switching to using either labels or uuids in fstab
and grub configs so that changes in partition numbers don't cause
problems.  Of course I've discovered for the Nth time in the past
10-15 years, that for the root= command line argument, the kernel
doesn't grok LABEL or UUID values -- it only understands device names
and PARTUUID.

--
Grant