System tweaks

  • SSH tweaks:

    • increased connection timeout

  • sysctl tweaks:

    • Increased file descriptor limit

    • Increased inotify limit

    • Enabled execshield

    • Network stack tuning (increased TCP buffer size, queue for input packets, selective logging, reverse path filtering, no routing modifications, prevent TCP time-wait attacks, prevent SYN attacks, etc…)

    • Discourage swapping idle processes

  • Bash tweaks:

    • readonly HISTFILE

    • readonly HISTIGNORE

    • don’t ignore commands

    • increased HISTSIZE

  • A swap file has been added

  • Improved I/O scheduler and I/O related tweaks