In previous posts, we covered the Linux file and directory structure. One very important directory in Linux is /var. This directory general contains the following subdirectories:
1. backups – primarily used by APT, this directory contains backups of package update states.
2. cache – certain applications use this directory to store temporary files.
3. lib – another library directory, much like /usr/lib
4. log – a storage directory for log files, both current and past.
5. mail – many mail servers, such as Postfix and Sendmail will use this directory.
6. opt – Used for various applications depending on distributions
7. spool – where your mail server stores mail before it is delivered.
8. lock – some applications will lock files and store them here.
9. tmp – storage of temporary files
10. www – Apache HTTP Server will use this for the web servers default directory, although virtual web servers may be stored elsewhere.