Hello

Do you know any tool (command line) to create an .iso of your system like this and then be installable? with your users, configuration files... everything

In summary, to be able to make backups and in case of loss of data or configurations, install the latest version from an .iso file.

You should always give information on the OS you're using for questions like this, however the keyword you want is "remaster" - search for that in conjunction with the OS name you're using you should get plenty of results.

(You might also want to consider whether a distinct backup process, plus a script that applies config/users/etc to a generic install is a better option.)

true is, the distribution is debian 10

that is not installation, but backup and restore. What I would suggest is: 1. make a backup of your setting, personal data and files and you can restore it at any time in the future. Do not need to reinstall anything.
2. you can always reinstall the OS, do not need to have full backup, just the setting, config and customization, which can be applied again in case of a clean install.

You can always use (for example) dd to make a copy of your disk which can be restored (using dd, without installation) if you wish, but that is not the preferred way (at least I think).

yes, Currently I use dd and pass a disk to an .img file (or tar.gz) what happens is that to restore it later I have to use a cdlive, mount the share and do another dd of the .img file to the sda partition... .and it works calro but it's a bit confusing,

which I think is something similar to what you say