diff --git a/docs/source/faq.rst b/docs/source/faq.rst index 361aac78c8dad37dc1690757fbeeb1cee62587fb..f3e3cf3f9bfd47c4d3f3ed891d948bdabd8fa73c 100644 --- a/docs/source/faq.rst +++ b/docs/source/faq.rst @@ -1,19 +1,24 @@ FAQ =================================== -*Q: My device is unreachable, but the device logs say it's running fine.* +Connecting to devices +-------------------------------------------------------------------------------------------------------------- + +My device is unreachable, but the device logs say it's running fine? +`````````````````````````````````````````````````````````````````````````````````````````````````````````````` The ``$HOSTNAME`` may have been incorrectly guessed by ``docker-compose/Makefile``, or you accidently set it to an incorrect value. See :ref:`corba`. -*Q: I get "API_CorbaException: TRANSIENT CORBA system exception: TRANSIENT_NoUsableProfile" when trying to connect to a device.* +I get "API_CorbaException: TRANSIENT CORBA system exception: TRANSIENT_NoUsableProfile" when trying to connect to a device? +```````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````` The ``$HOSTNAME`` may have been incorrectly guessed by ``docker-compose/Makefile``, or you accidently set it to an incorrect value. See :ref:`corba`. -*Q: The elk container won't start, saying "max virtual memory areas vm.max_map_count [65530] is too low"?* - -The ELK stack needs the ``vm.max_map_count`` sysctl kernel parameter to be at least 262144 to run. See :ref:`elk-kernel-settings`. +Docker +-------------------------------------------------------------------------------------------------------------- -*Q: How do I prevent my containers from starting when I boot my computer?* +How do I prevent my containers from starting when I boot my computer? +```````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````` You have to explicitly stop a container to prevent it from restarting. Use:: @@ -22,7 +27,11 @@ You have to explicitly stop a container to prevent it from restarting. Use:: or plain ``make stop`` to stop all of them. -*Q: Some SSTs/XSTs packets do arrive, but not all, and/or the matrices remain zero?* +SSTs/XSTs +-------------------------------------------------------------------------------------------------------------- + +Some SSTs/XSTs packets do arrive, but not all, and/or the matrices remain zero? +`````````````````````````````````````````````````````````````````````````````````````````````````````````````` So ``sst.nof_packets_received`` / ``xst.nof_packets_received`` is increasing, telling you packets are arriving. But they're apparently dropped or contain zeroes. First, check the following settings: @@ -36,7 +45,8 @@ Furthermore, the ``sst`` and ``xst`` devices expose several packet counters to i - ``nof_packets_dropped_R`` increases if packets could not be processed because the processing queue is full, so the CPU cannot keep up with the flow, - ``nof_payload_errors_R`` increases if the packet was marked by the FPGA to have an invalid payload, which causes the device to discard the packet, -*Q: I am not receiving any XSTs and/or SSTs packets from SDP!* +I am not receiving any XSTs and/or SSTs packets from SDP! +`````````````````````````````````````````````````````````````````````````````````````````````````````````````` Are you sure? If ``sst.nof_packets_received`` / ``xst.nof_packets_received`` is actually increasing, the packets are arriving, but are not parsable by the SST/XST device. If so, see the previous question. @@ -60,7 +70,8 @@ Many settings need to be correct for the statistics emitted by the SDP FPGAs to If this fails, see the next question. -*Q: I am still not receiving XSTs and/or SSTs, even though the settings appear correct!* +I am still not receiving XSTs and/or SSTs, even though the settings appear correct! +`````````````````````````````````````````````````````````````````````````````````````````````````````````````` Let's see where the packets get stuck. Let us assume your MTU=9000 network interface is called ``em2`` (see ``ip addr`` to check): @@ -97,3 +108,11 @@ Let's see where the packets get stuck. Let us assume your MTU=9000 network inter - If not, Linux is not routing the packets to the docker container correctly. - If still on error was found, you've likely hit a bug in our software. + +Other containers +-------------------------------------------------------------------------------------------------------------- + +The ELK container won't start, saying "max virtual memory areas vm.max_map_count [65530] is too low"? +`````````````````````````````````````````````````````````````````````````````````````````````````````````````` + +The ELK stack needs the ``vm.max_map_count`` sysctl kernel parameter to be at least 262144 to run. See :ref:`elk-kernel-settings`.