On Wed, Dec 14, 2011 at 4:30 AM, Jan Safranek <jsafr...@redhat.com> wrote:
> New documentation file is added. It should describe how systemd and > libcgroup should work together and how to configure a system to have > control groups created by libcgroup's cgconfig service. > > I'm going to install this README into /usr/share/doc/libcgroup-*/. > > I know I am not Shakespeare and also English is not my mother language, > feel > free to comment also the style and grammar. Missing/wrong articles is my > speciality :). > > Signed-off-by: Jan Safranek <jsafr...@redhat.com> > --- > > README_systemd | 68 > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 68 insertions(+), 0 deletions(-) > create mode 100644 README_systemd > > diff --git a/README_systemd b/README_systemd > new file mode 100644 > index 0000000..3bb2f6b > --- /dev/null > +++ b/README_systemd > @@ -0,0 +1,68 @@ > +Integration with systemd > +======================== > + > +systemd is a system and service manager for Linux, compatible with SysV > +and LSB init scripts. systemd heavily uses control groups to manage and > control > +services. > + > +Most of the libcgroup tools and APIs can be safely used on systems with > systemd > +without any problems. This document tries to describe how to configure > systemd > +and libcgroup so they can safely live together and mutually benefit from > each > +other. > + > +References > +========== > +[1] http://www.freedesktop.org/wiki/Software/systemd > +Systemd home page. > + > +[2] http://www.freedesktop.org/wiki/Software/systemd/PaxControlGroups > +This is the most usefult document describing systemd expectations on > applications > +(incl. libcgroup tools). > + > + > +Compilation > +=========== > +As stated in [2], libcgroup should not touch "name=systemd" hierarchy. > Compile > +libcgroup with --enable-opaque-hierarchy configure option to do so: > + > +./configure --enable-opaque-hierarchy=name=systemd > + > +Libcgroup and all its tools won't then see the "name=systemd" hierarchy > at all. > +For example, lsgcroup won't show it's content and cgclear won't remove it. > + > + > +Startup and services > +==================== > + > +Systemd automatically mounts all available controllers on system boot > ("cpu" > +and "cpuacct" together in one hierarchy by default) and can automatically > put > +service processes into control groups with configured parameters - by > default, > +each service is automatically put into "cpu,cpuacct:/system/$service_name" > +control group. System admin has full control on parameters of each group > and +also which controllers are used. Consult systemd documentation, mainly > The System Administrator has full control of parameters in each group and of which controllers are used +systemd.conf(5) and systemd.exec(5), for details. > + > +In vast majority of use cases, this should be enough and libcgroup does > not need > +to be used. > In *the* vast majority of use cases > + > +For specific use cases, e.g. when different tree of control groups is > needed, > when *a* different tree of control > +libcgroup provides cgconfig service. This service can create arbitrary > control > +group hierarchies. In this case, follow these steps: > + > +1. Set 'DefaultControllers=' in /etc/systemd/system.conf so systemd does > not > +create control groups for services automatically. > + > +2. Prepare /etc/cgconfig.conf and enable cgconfig service. The service > will > +parse /etc/cgconfig.conf file during machine boot and create all control > +groups which are defined in it. The service automatically sets '+t' > ("sticky") > +bit on tasks file as recommended in [2]. > + > +3. For each service that should start in specific control group, add > following > +lines into it's unit file: > add *the* following lines into *its* unit file > + After=cgconfig.service > + ControlGroup=<name of the control group(s)> > + > +This ensures the service is started only after cgconfig creates necessary > +hierarchy for it and also tells systemd into which control group should > be the +service started. > creates *the* necessary hierarchy for it. It also tells systemd which control group it should use to start the service. -kevin > + > > > > ------------------------------------------------------------------------------ > Cloud Computing - Latest Buzzword or a Glimpse of the Future? > This paper surveys cloud computing today: What are the benefits? > Why are businesses embracing it? What are its payoffs and pitfalls? > http://www.accelacomm.com/jaw/sdnl/114/51425149/ > _______________________________________________ > Libcg-devel mailing list > Libcg-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libcg-devel > ------------------------------------------------------------------------------ Cloud Computing - Latest Buzzword or a Glimpse of the Future? This paper surveys cloud computing today: What are the benefits? Why are businesses embracing it? What are its payoffs and pitfalls? http://www.accelacomm.com/jaw/sdnl/114/51425149/ _______________________________________________ Libcg-devel mailing list Libcg-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libcg-devel
