ElCuarteador
Thank you very much to all for the replies! I’m indeed learning a lot while trying to solve this problem.
I see now that the problem is the size of the rootfs file, too small and full now. It’s so small becuase that was the largest allowed when remastering after the installation of the kernel, I used to have one of 2.3GB or so before. Regarding what might be filling it up now: when I rebooted after running Live-USB Kernel Updater, I just ran antiX-Radio to test internet + audio and then tried running antiX Updater, nothing else. So, I guess rootfs must have something downloaded in the initial steps of the update, or something like that.
I tried the Resize Root Persistence option in the antiX Create or Resize Persistence tool in the CC, but I get an error message reading “Can’t resize %s while it is already mounted”. How do I unmount it? Can I really do that while running Live with static persistence?
Another easy alternative I read in your replies is to try remastering again. The available space now in the USB stick is more than 5 GB, so I could create a new rootfs file of sufficent size. Is it reasonable to try that in this situation? I already backed up all my data in the home folder just in case…
Other possible actions in your suggestions sound more difficult to do to me. I would need more detailed instructions to take them, in particular if they include running commands at the terminal. I know it’s a pain writing step-by-step instructions for more than 2-3 steps but… Perhaps resolving the questions above help solving the problem.
Thanks again to all for your patience and time!