If you are finding that space in your root directory is getting less and you are begining to feel the pinch, then maybe you should consider moving TeX-Live to your home directory.
You can move it using rsync with this command -
rsync -axvvES --info=progress2 --remove-source-files /usr/local/texlive /home/boudiccas && rm -rf /usr/local/texlive
This will move the file over and then it deletes the source file, very useful. Once everything is moved over, then you need to delete the source folders, and the only way that I've found is to launch nautilus as root and then delete the source texlive folders.
Then change the pathways in your .bashrc file -
TEXDIR="/home/boudiccas/texlive/2017" # TEXDIR="/usr/local/texlive/2016" export PATH=$TEXDIR/bin/x86_64-linux:$PATH # for 32-bit installation export INFOPATH=$INFOPATH:$TEXDIR/texmf-dist/doc/info export MANPATH=$MANPATH:$TEXDIR/texmf-dist/doc/man
And change '/usr/local/texlive/2017' to '/home/foo/texlive/2017', obviously changing foo to your login name.
Then just check that this doesn't need to be changed -
alias texupdate='env "PATH=$PATH" tlmgr update -all'
As you can see it didn't need to be changed. What this command does is make it easy to update your texlive installation, by just putting 'texupdate' in your terminal.
Then reboot, and once everything is back up and running, check that everything works as you expect.