And step by step, this is what I did in the meanwhile:

1. I installed refractasnapshot-base and refractasnapshot-gui, both v. 10.2.6 i386 from CERES (no problem installing on ASCII, btw). Ran refractasnapshot (no error messages regarding initrd with this new version) => no success
2. Uninstalled microcode packages, re-ran refractasnapshot => no success
3. Purged ALL the firmware packages, re-ran refractasnapshot => no success
4. At this point I was striving to realize what exactly is different between my two installs and why in one place it works and in the other one it doesn't. One thing that occured to me was that the live DVD was installed on an ext4 partition, whilst the regular DVD was installed on a JFS partition. So I cloned (with rsync) "the JFS install" to an ext4 partition (and updated fstab, initrd, grub). Booted "the ext4 clone", re-ran refractasnapshot => no success

What I'm going to do next is:
- upgrade the kernel, on the install where refractasnapshot works I have a 4.9.0-9-686 kernel, and on the other install a 4.9.0-6-686 kernel;
- search for differences between the two installs - in grub.conf, fstab... anything that could be responsible for the different behaviour.

So, if you want a portable package that you can use on either arch, or if you don't want to add ceres repos and install from there, I built the same version and uploaded it to sourceforge:
https://sourceforge.net/projects/refracta/files/tools/

The above might sound confusing. I tend to carry several deb packages of different versions of the tools on my live-usb sticks. (I try to carry the latest one, and the old ones just accumulate.)

fsmithred, about your questions:

encryption: no
swap: yes (4 Gb)
raid: no
lvm: no
microcode: I remember microcode packages being installed (and initrd being rebuilt) when, being in a hurry to install wifi drivers, I ran something like 'apt install firmware-*' (I installed ASCII from the regular DVD and no firmware got automatically installed, like with the live DVD). I'll post again tomorrow after testing refractasnapshot-mod. Thanks!

Thanks.

And version? repo..? 
I have installed now: ascii repos - refractasnapshot-base 10.1.1  (no errors)
I imagine to use:
ceres repo - refractasnapshot-base 10.2.3 (decompression error)

K...brb...

Download it, copy it to /usr/bin/refractasnapshot
Make it executable and run it 'refractasnapshot -d'

Note: Before you run it, edit /etc/refractasnapshot.conf and set save_work="yes". That way, if we need to make more changes to the initrd, you can just repack the iso without re-squashing. That takes less than a minute as opposed to however long it takes to run the whole thing. (10-40 minutes in my experience)

Edit: If you're using Refracta or other distro that defaults to xz compression on the initrd, use this one instead:
http://distro.ibiblio.org/refracta/misc … t-mod2.txt

I also took your advice and later updated refractasnapshot (I installed refractasnapshot-base_10.2.3~fsr_all.deb, it seems this is the newest). However, when running the new refractasnapshot, this is what happens:

Running updatedb...

/tmp/extracted /home/work
Decompession error...

So I had a look at /usr/bin/refractasnapshot (starting with line 321):

	COMPRESSION=$(file -L "$initrd_image" | egrep -o 'gzip compressed|XZ compressed')

	if [ "$COMPRESSION" = "gzip compressed" ]; then
		echo "Archive is gzip compressed..."
		zcat "$initrd_image" | cpio -i

	elif [ "$COMPRESSION" = "XZ compressed" ]; then
		echo "Archive is XZ compressed..."
		xzcat "$initrd_image" | cpio -d -i -m
	else
		echo "Decompession error..." && exit 1
	fi

However, on my machine, things look like this:

root@devuan:~# file -L /initrd.img
/initrd.img: ASCII cpio archive (SVR4 with no CRC)
root@devuan:~# ls -l /initrd.img
lrwxrwxrwx 1 root root 27 Jul  4 23:43 /initrd.img -> boot/initrd.img-4.9.0-6-686

I'd say that my initrd is not supported, but I don't know why/how, this is a simple ASCII i386 install made with the regular big DVD.

Best wishes,

Omnio

Take a look at /var/log/refractasnapshot.log (or something like that - I changed the name recently). I don't recall if that version is set to always run in debug mode or not. If the log has a lot of lines that start with + signs, then it's a debug log and it will probably tell what the problem is. If not, re-run 'refractasnapshot -d' or 'refractasnapshot-gui -d' and paste the log some place where I can see it. (email it to me if you want)

If you're creating a snapshot on a system that has an encrypted filesystem or a swap partition, you may need to remove a file or two from the initrd. There are instructions for that in /usr/share/doc/refractasnapshot-base/readme.refractasnapshot.txt.gz or from the Help choice in the program. Or you could use the latest version and it will make those changes for you. 10.2.3 is here (cli and gui will work on ascii) - https://sourceforge.net/projects/refracta/files/tools/