units: run sysctl stuff only when /proc/sys is actually writable, to quieten containe...

[thirdparty/systemd.git] / README

systemd System and Service Manager

DETAILS:
        http://0pointer.de/blog/projects/systemd.html

WEB SITE:
        http://www.freedesktop.org/wiki/Software/systemd

GIT:
        git://anongit.freedesktop.org/systemd/systemd
        ssh://git.freedesktop.org/git/systemd/systemd

GITWEB:
        http://cgit.freedesktop.org/systemd/systemd

MAILING LIST:
        http://lists.freedesktop.org/mailman/listinfo/systemd-devel
        http://lists.freedesktop.org/mailman/listinfo/systemd-commits

IRC:
        #systemd on irc.freenode.org

BUG REPORTS:
        https://bugs.freedesktop.org/enter_bug.cgi?product=systemd

AUTHOR:
        Lennart Poettering
        Kay Sievers
        ...and many others

LICENSE:
        LGPLv2.1+ for all code
        - except sd-daemon.[ch] and sd-readahead.[ch] which are MIT
        - except src/udev/ which is GPLv2.0+, excluding
          src/udev/libudev* which is LGPLv2.1+

REQUIREMENTS:
        Linux kernel >= 2.6.39
                with devtmpfs
                with cgroups (but it's OK to disable all controllers)
                optional but strongly recommended: autofs4, ipv6
        libudev >= 172
        dbus >= 1.4.0
        libcap
        PAM >= 1.1.2 (optional)
        libcryptsetup (optional)
        libaudit (optional)
        libselinux (optional)
        tcpwrappers (optional)

        When you build from git you need the following additional dependencies:

        docbook-xsl
        xsltproc
        automake
        autoconf
        libtool
        gperf
        make, gcc, and similar tools

        During runtime you need the following dependencies:

        util-linux > v2.18 (requires fsck -l, agetty -s)
        sulogin (from sysvinit-tools, optional but recommended)
        plymouth (optional)
        dracut (optional)

        When systemd-hostnamed is used it is strongly recommended to
        install nss-myhostname to ensure that in a world of
        dynamically changing hostnames the hostname stays resolveable
        under all circumstances. In fact, systemd-hostnamed will warn
        if nss-myhostname is not installed. Packagers are encouraged to
        add a dependency on nss-myhostname to the package that
        includes systemd-hostnamed.

        Note that D-Bus can link against libsystemd-login.so, which
        results in a cyclic build dependency. To accomodate for this
        please build D-Bus without systemd first, then build systemd,
        then rebuild D-Bus with systemd support.

WARNINGS:
        systemd will warn you during boot if /etc/mtab is not a
        symlink to /proc/mounts. Please ensure that /etc/mtab is a
        proper symlink.

        systemd will warn you during boot if /usr is on a different
        file system than /. While in systemd itself very little will
        break if /usr is on a separate partition many of its
        dependencies very likely will break sooner or later in one
        form or another. For example udev rules tend to refer to
        binaries in /usr, binaries that link to libraries in /usr or
        binaries that refer to data files in /usr. Since these
        breakages are not always directly visible systemd will warn
        about this, since this kind of file system setup is not really
        supported anymore by the basic set of Linux OS components.

        For more information on this issue consult
        http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken

ENGINEERING AND CONSULTING SERVICES:
        ProFUSION <http://profusion.mobi> offers professional
        engineering and consulting services for systemd for embedded
        and other use. Please contact Gustavo Barbieri
        <barbieri@profusion.mobi> for more information.

        Disclaimer: This notice is not a recommendation or official
        endorsement. However, ProFUSION's upstream work has been very
        beneficial for the systemd project.