systemd System and Service Manager DETAILS: WEB SITE: GIT: git:// ssh:// GITWEB: MAILING LIST: IRC: #systemd on BUG REPORTS: AUTHOR: Lennart Poettering Kay Sievers ...and many others LICENSE: LGPLv2.1+ for all code - except sd-readahead.[ch] which is MIT - except src/shared/MurmurHash2.c which is Public Domain - except src/shared/siphash24.c which is CC0 Public Domain - except src/journal/lookup3.c which is Public Domain - except src/udev/* which is (currently still) GPLv2, GPLv2+ REQUIREMENTS: Linux kernel >= 3.0 Linux kernel >= 3.3 for loop device partition support features with nspawn Linux kernel >= 3.8 for Smack support Kernel Config Options: CONFIG_DEVTMPFS CONFIG_CGROUPS (it is OK to disable all controllers) CONFIG_INOTIFY_USER CONFIG_SIGNALFD CONFIG_TIMERFD CONFIG_EPOLL CONFIG_NET CONFIG_SYSFS CONFIG_PROC_FS CONFIG_FHANDLE (libudev, mount and bind mount handling) Udev will fail to work with the legacy layout: CONFIG_SYSFS_DEPRECATED=n Legacy hotplug slows down the system and confuses udev: CONFIG_UEVENT_HELPER_PATH="" Userspace firmware loading is deprecated, will go away, and sometimes causes problems: CONFIG_FW_LOADER_USER_HELPER=n Some udev rules and virtualization detection relies on it: CONFIG_DMIID Support for some SCSI devices serial number retrieval, to create additional symlinks in /dev/disk/ and /dev/tape: CONFIG_BLK_DEV_BSG Required for PrivateNetwork in service units: CONFIG_NET_NS Optional but strongly recommended: CONFIG_IPV6 CONFIG_AUTOFS4_FS CONFIG_TMPFS_POSIX_ACL CONFIG_TMPFS_XATTR CONFIG_SECCOMP For systemd-bootchart, several proc debug interfaces are required: CONFIG_SCHEDSTATS CONFIG_SCHED_DEBUG For UEFI systems: CONFIG_EFIVAR_FS CONFIG_EFI_PARTITION Note that kernel auditing is broken when used with systemd's container code. When using systemd in conjunction with containers, please make sure to either turn off auditing at runtime using the kernel command line option "audit=0", or turn it off at kernel compile time using: CONFIG_AUDIT=n If systemd is compiled with libseccomp support on architectures which do not use socketcall() and where seccomp is supported (this effectively means x86-64 and ARM, but excludes 32-bit x86!), then nspawn will now install a work-around seccomp filter that makes containers boot even with audit being enabled. This works correctly only on kernels 3.14 and newer though. TL;DR: turn audit off, still. glibc >= 2.14 libcap libseccomp >= 1.0.0 (optional) libblkid >= 2.20 (from util-linux) (optional) libkmod >= 15 (optional) PAM >= 1.1.2 (optional) libcryptsetup (optional) libaudit (optional) libacl (optional) libattr (optional) libselinux (optional) liblzma (optional) libgcrypt (optional) libqrencode (optional) libmicrohttpd (optional) libpython (optional) make, gcc, and similar tools During runtime, you need the following additional dependencies: util-linux >= v2.19 (requires fsck -l, agetty -s), v2.21 required for tests in test/ dbus >= 1.4.0 (strictly speaking optional, but recommended) sulogin (from util-linux >= 2.22 or sysvinit-tools, optional but recommended, required for tests in test/) dracut (optional) PolicyKit (optional) When building from git, you need the following additional dependencies: docbook-xsl xsltproc automake autoconf libtool intltool gperf gtkdocize (optional) python (optional) python-lxml (optional, but required to build the indices) sphinx (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 resolvable under all circumstances. In fact, systemd-hostnamed will warn if nss-myhostname is not installed. To build HTML documentation for python-systemd using sphinx, please first install systemd (using 'make install'), and then invoke sphinx-build with 'make sphinx-', with being 'html' or 'latexpdf'. If using DESTDIR for installation, pass the same DESTDIR to 'make sphinx-html' invocation. USERS AND GROUPS: Default udev rules use the following standard system group names, which need to be resolvable by getgrnam() at any time, even in the very early boot stages, where no other databases and network are available: tty, dialout, kmem, video, audio, lp, floppy, cdrom, tape, disk During runtime, the journal daemon requires the "systemd-journal" system group to exist. New journal files will be readable by this group (but not writable), which may be used to grant specific users read access. It is also recommended to grant read access to all journal files to the system groups "wheel" and "adm" with a command like the following in the post installation script of the package: # setfacl -nm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/ The journal gateway daemon requires the "systemd-journal-gateway" system user and group to exist. During execution this network facing service will drop privileges and assume this uid/gid for security reasons. 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. systemd requires that the /run mount point exists. systemd also requires that /var/run is a a symlink to /run. For more information on this issue consult To run systemd under valgrind, compile with VALGRIND defined (e.g. ./configure CPPFLAGS='... -DVALGRIND=1'). Otherwise, false positives will be triggered by code which violates some rules but is actually safe.