Re: Boot question

[Pascal-liste]

Le 03/04/2021 à 21:04, jmh6@nhfn.net a écrit :
>    I recently 'copied' a linux OS from a 16MB SD card to a 32MB card.

How ?

>    Eventually I figured out UUID enough to get that new device with 
> different UUIDs up and running.
>
>    After linux loads and the initrd are loaded, the linux kernel tries 
> to find the 'boot SD'.

The Linux kernel does not care about the boot device. Boot has already 
happened. The boot device is not necessary any more.

>   The /dev/sdc loads

What do you mean exactly ?

> but the partitions are not yet visible

What do you mean exactly ?

> and the boot aborts and prints a message 
> suggesting that a bigger 'rootdelay' be used.

Please post the full message.

>    I then enter a line 'rootdelay=20' and ctrl-alt-del reboot. Often but 
> not always starts successfully.

Where do you enter the line ? At the initramfs shell ? It is useless.
This is a kernel parameter. Kernel parameters must be added to the 
kernel command line passed by the boot loader, either in 
/boot/grub/grub.cfg or at boot time in the menu entry editor (type "e").

>    I am wondering if/how I can tell this last stage of the boot process 
> to use the UUID device rather than try to use /dev/sdc? Perhaps some 
> line in grub or in /etc?

In /boot/grub/grub.cfg
If the linux command contains root=/dev/sdxx, you should change it into 
root=UUID=xxxx.

>    The OS is vmlinuz-4.9.212-antix.1-486-smp.

This is a Linux kernel image, not an OS.