backup of repository

Hello,

just a small question. Reading the documentation there are 2 main ways of
backing up the repository:
 * using dump
 * using hotbackup

I'm interested in incremental backup because I don't want to have to take a
full backup each time. Is it safe to do an incremental backup using dump (of
revisions that were commited) while the repository is online?

What is the purpose of the hotbackup-script? Why is it needed of the
dump-command works fine?

Thank you and greetigs,

Michel