Finish pre-demo slides

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Vincent Ambo 2016-01-21 14:40:11 +01:00
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@ -51,4 +51,19 @@ systemd.device - trigger units when certain devices are connected
systemd.mount - systemd equivalent of fstab entries
systemd.swap - like mount
systemd.slice - unit groups for resource management purposes
... and a few more specialised ones
... and a few more specialised ones
### 10
Linux cgroups are a new resource management feature added quite a long time ago, but not used much.
Cgroups can be created manually and processes can be moved into them in order to control resource utilisation
Few people used them before systemd, limits.conf was often much easier but not as fine-grained
Systemd changed this
### 11
Systemd collects standard output and stderr from all processes into its journal system
they provide a tool for querying the log, for example grouping service logs together with correct timestamps, querying,
### 12
Systemd tooling, most important one is systemctl for general service management
journalctl is the query and management tool for journald
systemd-analyze is used for figuring out performance issues, for example by analysing the boot process, can make cool graphs of dependencies
systemd-cgtop is like top, but not on a process level - it's on a cgroup/slice level, shows combined usage of cgroups
systemd-cgls lists contents of systemd's cgroups to see which services are in what group
there also exist a bunch of others that we'll skip for now

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@ -87,7 +87,40 @@
\end{code}
\end{frame}
\begin{frame}{}
\begin{frame}{Resource management}
Systemd utilises Linux \texttt{cgroups} for resource management, specifically CPU, disk I/O and memory usage.
\begin{itemize}
\item Hierarchical setup of groups makes it easy to limit resources for a set of services
\item Units can be attached to a \texttt{systemd.slice} for controlling resources for a group of services
\item Resource limits can also be specified directly in the unit
\end{itemize}
\end{frame}
\begin{frame}{journald}
Systemd comes with an integrated log management solution, replacing software such as \texttt{syslog-ng}.
\begin{itemize}
\item All process output is collected in the journal
\item \texttt{journalctl} tool provides many options for querying and tailing logs
\item Children of processes automatically log to the journal as well
\item \textbf{Caveat:} Hard to learn initially
\end{itemize}
\end{frame}
\begin{frame}{Systemd tooling}
A variety of CLI-tools exist for managing systemd systems.
\begin{code}
\begin{itemize}
\item systemctl
\item journalctl
\item systemd-analyze
\item systemd-cgtop
\item systemd-cgls
\end{itemize}
\end{code}
Let's look at some of them.
\end{frame}
\section{Demo}