]> git.proxmox.com Git - systemd.git/blob - README
Enable seccomp support on powerpc, ppc64el, and s390x
[systemd.git] / README
1 systemd System and Service Manager
2
3 DETAILS:
4 http://0pointer.de/blog/projects/systemd.html
5
6 WEB SITE:
7 http://www.freedesktop.org/wiki/Software/systemd
8
9 GIT:
10 git@github.com:systemd/systemd.git
11 https://github.com/systemd/systemd.git
12
13 GITWEB:
14 https://github.com/systemd/systemd
15
16 MAILING LIST:
17 http://lists.freedesktop.org/mailman/listinfo/systemd-devel
18 http://lists.freedesktop.org/mailman/listinfo/systemd-commits
19
20 IRC:
21 #systemd on irc.freenode.org
22
23 BUG REPORTS:
24 https://github.com/systemd/systemd/issues
25
26 AUTHOR:
27 Lennart Poettering
28 Kay Sievers
29 ...and many others
30
31 LICENSE:
32 LGPLv2.1+ for all code
33 - except src/basic/MurmurHash2.c which is Public Domain
34 - except src/basic/siphash24.c which is CC0 Public Domain
35 - except src/journal/lookup3.c which is Public Domain
36 - except src/udev/* which is (currently still) GPLv2, GPLv2+
37
38 REQUIREMENTS:
39 Linux kernel >= 3.11
40 Linux kernel >= 4.2 for unified cgroup hierarchy support
41
42 Kernel Config Options:
43 CONFIG_DEVTMPFS
44 CONFIG_CGROUPS (it is OK to disable all controllers)
45 CONFIG_INOTIFY_USER
46 CONFIG_SIGNALFD
47 CONFIG_TIMERFD
48 CONFIG_EPOLL
49 CONFIG_NET
50 CONFIG_SYSFS
51 CONFIG_PROC_FS
52 CONFIG_FHANDLE (libudev, mount and bind mount handling)
53
54 udev will fail to work with the legacy sysfs layout:
55 CONFIG_SYSFS_DEPRECATED=n
56
57 Legacy hotplug slows down the system and confuses udev:
58 CONFIG_UEVENT_HELPER_PATH=""
59
60 Userspace firmware loading is not supported and should
61 be disabled in the kernel:
62 CONFIG_FW_LOADER_USER_HELPER=n
63
64 Some udev rules and virtualization detection relies on it:
65 CONFIG_DMIID
66
67 Support for some SCSI devices serial number retrieval, to
68 create additional symlinks in /dev/disk/ and /dev/tape:
69 CONFIG_BLK_DEV_BSG
70
71 Required for PrivateNetwork and PrivateDevices in service units:
72 CONFIG_NET_NS
73 CONFIG_DEVPTS_MULTIPLE_INSTANCES
74 Note that systemd-localed.service and other systemd units use
75 PrivateNetwork and PrivateDevices so this is effectively required.
76
77 Optional but strongly recommended:
78 CONFIG_IPV6
79 CONFIG_AUTOFS4_FS
80 CONFIG_TMPFS_XATTR
81 CONFIG_{TMPFS,EXT4,XFS,BTRFS_FS,...}_POSIX_ACL
82 CONFIG_SECCOMP
83 CONFIG_CHECKPOINT_RESTORE (for the kcmp() syscall)
84
85 Required for CPUShares= in resource control unit settings
86 CONFIG_CGROUP_SCHED
87 CONFIG_FAIR_GROUP_SCHED
88
89 Required for CPUQuota= in resource control unit settings
90 CONFIG_CFS_BANDWIDTH
91
92 For systemd-bootchart, several proc debug interfaces are required:
93 CONFIG_SCHEDSTATS
94 CONFIG_SCHED_DEBUG
95
96 For UEFI systems:
97 CONFIG_EFIVAR_FS
98 CONFIG_EFI_PARTITION
99
100 We recommend to turn off Real-Time group scheduling in the
101 kernel when using systemd. RT group scheduling effectively
102 makes RT scheduling unavailable for most userspace, since it
103 requires explicit assignment of RT budgets to each unit whose
104 processes making use of RT. As there's no sensible way to
105 assign these budgets automatically this cannot really be
106 fixed, and it's best to disable group scheduling hence.
107 CONFIG_RT_GROUP_SCHED=n
108
109 Note that kernel auditing is broken when used with systemd's
110 container code. When using systemd in conjunction with
111 containers, please make sure to either turn off auditing at
112 runtime using the kernel command line option "audit=0", or
113 turn it off at kernel compile time using:
114 CONFIG_AUDIT=n
115 If systemd is compiled with libseccomp support on
116 architectures which do not use socketcall() and where seccomp
117 is supported (this effectively means x86-64 and ARM, but
118 excludes 32-bit x86!), then nspawn will now install a
119 work-around seccomp filter that makes containers boot even
120 with audit being enabled. This works correctly only on kernels
121 3.14 and newer though. TL;DR: turn audit off, still.
122
123 glibc >= 2.16
124 libcap
125 libmount >= 2.27.1 (from util-linux)
126 libseccomp >= 1.0.0 (optional)
127 libblkid >= 2.24 (from util-linux) (optional)
128 libkmod >= 15 (optional)
129 PAM >= 1.1.2 (optional)
130 libcryptsetup (optional)
131 libaudit (optional)
132 libacl (optional)
133 libselinux (optional)
134 liblzma (optional)
135 liblz4 >= 119 (optional)
136 libgcrypt (optional)
137 libqrencode (optional)
138 libmicrohttpd (optional)
139 libpython (optional)
140 libidn (optional)
141 elfutils >= 158 (optional)
142 make, gcc, and similar tools
143
144 During runtime, you need the following additional
145 dependencies:
146
147 util-linux >= v2.27.1 required
148 dbus >= 1.4.0 (strictly speaking optional, but recommended)
149 dracut (optional)
150 PolicyKit (optional)
151
152 When building from git, the following tools are needed:
153
154 pkg-config
155 docbook-xsl
156 xsltproc
157 automake
158 autoconf
159 libtool
160 intltool
161 gperf
162 python (optional)
163 python-lxml (optional, but required to build the indices)
164
165 The build system is initialized with ./autogen.sh. A tar ball
166 can be created with:
167 git archive --format=tar --prefix=systemd-222/ v222 | xz > systemd-222.tar.xz
168
169 When systemd-hostnamed is used, it is strongly recommended to
170 install nss-myhostname to ensure that, in a world of
171 dynamically changing hostnames, the hostname stays resolvable
172 under all circumstances. In fact, systemd-hostnamed will warn
173 if nss-myhostname is not installed.
174
175 USERS AND GROUPS:
176 Default udev rules use the following standard system group
177 names, which need to be resolvable by getgrnam() at any time,
178 even in the very early boot stages, where no other databases
179 and network are available:
180
181 audio, cdrom, dialout, disk, input, kmem, lp, tape, tty, video
182
183 During runtime, the journal daemon requires the
184 "systemd-journal" system group to exist. New journal files will
185 be readable by this group (but not writable), which may be used
186 to grant specific users read access. In addition, system
187 groups "wheel" and "adm" will be given read-only access to
188 journal files using systemd-tmpfiles.service.
189
190 The journal gateway daemon requires the
191 "systemd-journal-gateway" system user and group to
192 exist. During execution this network facing service will drop
193 privileges and assume this uid/gid for security reasons.
194
195 Similarly, the NTP daemon requires the "systemd-timesync" system
196 user and group to exist.
197
198 Similarly, the network management daemon requires the
199 "systemd-network" system user and group to exist.
200
201 Similarly, the name resolution daemon requires the
202 "systemd-resolve" system user and group to exist.
203
204 Similarly, the kdbus dbus1 proxy daemon requires the
205 "systemd-bus-proxy" system user and group to exist.
206
207 NSS:
208 systemd ships with three NSS modules:
209
210 nss-myhostname resolves the local hostname to locally
211 configured IP addresses, as well as "localhost" to
212 127.0.0.1/::1.
213
214 nss-resolve enables DNS resolution via the systemd-resolved
215 DNS/LLMNR caching stub resolver "systemd-resolved".
216
217 nss-mymachines enables resolution of all local containers
218 registered with machined to their respective IP addresses.
219
220 To make use of these NSS modules, please add them to the
221 "hosts: " line in /etc/nsswitch.conf. The "resolve" module
222 should replace the glibc "dns" module in this file.
223
224 The three modules should be used in the following order:
225
226 hosts: files mymachines resolve myhostname
227
228 SYSV INIT.D SCRIPTS:
229 When calling "systemctl enable/disable/is-enabled" on a unit which is a
230 SysV init.d script, it calls /usr/lib/systemd/systemd-sysv-install;
231 this needs to translate the action into the distribution specific
232 mechanism such as chkconfig or update-rc.d. Packagers need to provide
233 this script if you need this functionality (you don't if you disabled
234 SysV init support).
235
236 Please see src/systemctl/systemd-sysv-install.SKELETON for how this
237 needs to look like, and provide an implementation at the marked places.
238
239 WARNINGS:
240 systemd will freeze execution during boot if /etc/mtab exists
241 but is not a symlink to /proc/mounts. Please ensure that
242 /etc/mtab is a proper symlink.
243
244 systemd will warn you during boot if /usr is on a different
245 file system than /. While in systemd itself very little will
246 break if /usr is on a separate partition, many of its
247 dependencies very likely will break sooner or later in one
248 form or another. For example, udev rules tend to refer to
249 binaries in /usr, binaries that link to libraries in /usr or
250 binaries that refer to data files in /usr. Since these
251 breakages are not always directly visible, systemd will warn
252 about this, since this kind of file system setup is not really
253 supported anymore by the basic set of Linux OS components.
254
255 systemd requires that the /run mount point exists. systemd also
256 requires that /var/run is a symlink to /run.
257
258 For more information on this issue consult
259 http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken
260
261 To run systemd under valgrind, compile with VALGRIND defined
262 (e.g. ./configure CPPFLAGS='... -DVALGRIND=1'). Otherwise,
263 false positives will be triggered by code which violates
264 some rules but is actually safe.
265
266 Currently, systemd-timesyncd defaults to use the Google NTP
267 servers if not specified otherwise at configure time. You
268 really should not ship an OS or device with this default
269 setting. See DISTRO_PORTING for details.