download http://http.us.debian.org/debian/poo...03-1_amd64.deb
download http://http.us.debian.org/debian/poo...03-1_amd64.deb

extract a squashfs file type inside Lubuntu live .iso

then ./squashfuse filesystem.squash somewhere mountpoint
I can list the directories like usr/ lib/ bin/ and size are...
du -hs usr/ 1.5G
du -hs lib/ 150M
du -hs bin/ 13M

I can cp the whole mountpoint and put what I need the executable into the "folder". I mean I add some executable and also delete some files not need inside the folder.

then what command to "zip" my folder back to squashfs type ?
https://packages.debian.org/buster/squashfs-tools

if the output by mkfs.squash mksquashfs is ok, what command create boot sector .iso wrap all the fileS ?