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+.. _system_option:
+
+#######
+Options
+#######
+
+This chapter describe the possibilities of advanced system behavior.
+
+*******
+General
+*******
+
+.. cfgcmd:: set system option ctrl-alt-delete <ignore | reboot | poweroff>
+
+   Action which will be run once the ctrl-alt-del keystroke is received.
+
+.. cfgcmd:: set system option reboot-on-panic
+
+   Automatically reboot system on kernel panic after 60 seconds.
+
+.. cfgcmd:: set system option startup-beep
+
+    Play an audible beep to the system speaker when system is ready.
+
+***********
+HTTP client
+***********
+
+.. cfgcmd:: set system option http-client source-address <address>
+
+   Several commands utilize curl to initiate transfers. Configure the local
+   source IPv4/IPv6 address used for all CURL operations.
+
+.. cfgcmd:: set system option http-client source-interface <interface>
+
+   Several commands utilize curl to initiate transfers. Configure the local
+   source interface used for all CURL operations.
+
+.. note:: `source-address` and `source-interface` can not be used at the same time.
+
+***************
+Keyboard Layout
+***************
+
+When starting a VyOS live system (the installation CD) the configured keyboard
+layout defaults to US. As this might not suite everyones use case you can adjust
+the used keyboard layout on the system console.
+
+.. cfgcmd:: set system option keyboard-layout <us | fr | de | fi | no | dk>
+
+  Change system keyboard layout to given language.
+
+  Defaults to ``us``.
+
+  .. note:: Changing the keymap only has an effect on the system console, using
+    SSH oder Serial remote access to the device is not affected as the keyboard
+    layout here corresponds to your access system.
+
+.. _system_options_performance:
+
+***********
+Performance
+***********
+
+As more and more routers run on Hypervisors, expecially with a :abbr:`NOS
+(Network Operating System)` as VyOS, it makes fewer and fewer sense to use
+static resource bindings like ``smp-affinity`` as present in VyOS 1.2 and
+earlier to pin certain interrupt handlers to specific CPUs.
+
+We now utilize `tuned` for dynamic resource balancing based on profiles.
+
+  .. seealso:: https://access.redhat.com/sites/default/files/attachments/201501-perf-brief-low-latency-tuning-rhel7-v2.1.pdf
+
+.. cfgcmd:: set system option performance < throughput | latency >
+
+  Configure one of the predefined system performance profiles.
+
+  * ``throughput``: A server profile focused on improving network throughput.
+    This profile favors performance over power savings by setting ``intel_pstate``
+    and ``max_perf_pct=100`` and increasing kernel network buffer sizes.
+
+    It enables transparent huge pages, and uses cpupower to set the performance
+    cpufreq governor. It also sets ``kernel.sched_min_granularity_ns`` to 10 us,
+    ``kernel.sched_wakeup_granularity_ns`` to 15 uss, and ``vm.dirty_ratio`` to
+    40%.
+
+  * ``latency``: A server profile focused on lowering network latency.
+    This profile favors performance over power savings by setting ``intel_pstate``
+    and ``min_perf_pct=100``.
+
+    It disables transparent huge pages, and automatic NUMA balancing. It also
+    uses cpupower to set the performance cpufreq governor, and requests a
+    cpu_dma_latency value of 1. It also sets busy_read and busy_poll times to
+    50 us, and tcp_fastopen to 3.