There is a ubuntu server, home pc. On it some sites are turning + ftp file of a sphere.
Questions the following, how can you secure the server to the maximum?
- Backups are made regularly
- Nginx, as the front-end to the Apache.
- mysql is, every site with its user is connected to it. Have phpmyadmin
- Ssh + ftp (proftpd) posted
Questions:
- What actions need to be taken to make everything as safe as possible?
- What should be read on the topic?
- What are some elementary actions worth taking, where to read about them? (from the category do not sit under the root, complex passwords, different passwords everywhere, etc.)
- What console antivirus advise?
- What you need to check regularly logs? What and where to read them?
- Any books and related articles are welcome.