non-transient services (i.e. those defined with unit files on disk)
we will continue to default to Type=simple.
+ * The Linux kernel's current default RLIMIT_NOFILE resource limit for
+ userspace processes is set to 1024 (soft) and 4096
+ (hard). Previously, systemd passed this on unmodified to all
+ processes it forked off. With this systemd release the hard limit
+ systemd passes on is increased to 256K, overriding the kernel's
+ defaults and substantially increasing the number of simultaneous file
+ descriptors unprivileged userspace processes can allocate. Note that
+ the soft limit remains at 1024 for compatibility reasons: the
+ traditional UNIX select() call cannot deal with file descriptors >=
+ 1024 and increasing the soft limit globally might thus result in
+ programs unexpectedly allocating a high file descriptor and thus
+ failing abnormally when attempting to use it with select() (of
+ course, programs shouldn't use select() anymore, and prefer
+ poll()/epoll, but the call unfortunately remains undeservedly popular
+ at this time). This change reflects the fact that file descriptor
+ handling in the Linux kernel has been optimized in more recent
+ kernels and allocating large numbers of them should be much cheaper
+ both in memory and in performance than it used to be. Programs that
+ want to take benefit of the increased limit have to "opt-in" into
+ high file descriptors explicitly by setting their soft limit to the
+ hard limit during initialization. Of course, when doing that they
+ must do this acknowledging the fact that they cannot use select()
+ anymore (and neither can any shared library they use — or any shared
+ library used by any shared library they use and so on).
+
+ * The fs.nr_open and fs.file-max sysctls are now automatically bumped
+ to the highest possible values, as separate accounting of file
+ descriptors is no longer necessary, as memcg tracks them correctly as
+ part of the memory accounting anyway. Thus, from the four limits on
+ file descriptors currently enforced (fs.file-max, fs.nr_open,
+ RLIMIT_NOFILE hard, RLIMIT_NOFILE soft) we turn off the first two,
+ and keep only the latter two. A set of build-time options
+ (-Dbump-proc-sys-fs-file-max=no and -Dbump-proc-sys-fs-nr-open=no)
+ has been added to revert this change in behaviour, which might be
+ an option for systems that turn off memcg in the kernel.
+
+ * When no /etc/locale.conf file exists (and hence no locale settings
+ are in place), systemd will now use the "C.UTF-8" locale by default,
+ and set LANG= to it. This locale is supported by various
+ distributions including Fedora, with clear indications that upstream
+ glibc is going to make it available too. This locale enables UTF-8
+ mode by default, which appears appropriate for 2018.
+
CHANGES WITH 239:
* NETWORK INTERFACE DEVICE NAMING CHANGES: systemd-udevd's "net_id"
* systemd-resolved.service and systemd-networkd.service now set
DynamicUser=yes. The users systemd-resolve and systemd-network are
- not created by systemd-sysusers.
+ not created by systemd-sysusers anymore.
+
+ NOTE: This has a chance of breaking nss-ldap and similar NSS modules
+ that embedd a network facing module into any process using getpwuid()
+ or related call: the dynamic allocation of the user ID for
+ systemd-resolved.service means the service manager has to check NSS
+ if the user name is already taken when forking off the service. Since
+ the user in the common case won't be defined in /etc/passwd the
+ lookup is likely to trigger nss-ldap which in turn might use NSS to
+ ask systemd-resolved for hostname lookups. This will hence result in
+ a deadlock: a user name lookup in order to start
+ systemd-resolved.service will result in a host name lookup for which
+ systemd-resolved.service needs to be started already. There are
+ multiple ways to work around this problem: pre-allocate the
+ "systemd-resolve" user on such systems, so that nss-ldap won't be
+ triggered; or use a different NSS package that doesn't do networking
+ in-process but provides a local asynchronous name cache; or configure
+ the NSS package to avoid lookups for UIDs in the range `pkg-config
+ systemd --variable=dynamicuidmin` … `pkg-config systemd
+ --variable=dynamicuidmax`, so that it does not consider itself
+ authoritative for the same UID range systemd allocates dynamic users
+ from.
* The systemd-resolve tool has been renamed to resolvectl (it also
remains available under the old name, for compatibility), and its
* New documentation has been added to document cgroups delegation,
portable services and the various code quality tools we have set up:
- https://github.com/systemd/systemd/blob/master/doc/CGROUP_DELEGATION.md
- https://github.com/systemd/systemd/blob/master/doc/PORTABLE_SERVICES.md
- https://github.com/systemd/systemd/blob/master/doc/CODE_QUALITY.md
+ https://github.com/systemd/systemd/blob/master/docs/CGROUP_DELEGATION.md
+ https://github.com/systemd/systemd/blob/master/docs/PORTABLE_SERVICES.md
+ https://github.com/systemd/systemd/blob/master/docs/CODE_QUALITY.md
* The Boot Loader Specification has been added to the source tree.
- https://github.com/systemd/systemd/blob/master/doc/BOOT_LOADER_SPECIFICATION.md
+ https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md
While moving it into our source tree we have updated it and further
changes are now accepted through the usual github PR workflow.
different from what the documentation said, and not particularly
useful, as repeated systemd-tmpfiles invocations would not be
idempotent and grow such files without bounds. With this release
- behaviour has been altered slightly, to match what the documentation
- says: lines of this type only have an effect if the indicated files
- don't exist yet, and only then the argument string is written to the
- file.
+ behaviour has been altered to match what the documentation says:
+ lines of this type only have an effect if the indicated files don't
+ exist yet, and only then the argument string is written to the file.
* FUTURE INCOMPATIBILITY: In systemd v238 we intend to slightly change
systemd-tmpfiles behaviour: previously, read-only files owned by root
* Documentation has been added that lists all of systemd's low-level
environment variables:
- https://github.com/systemd/systemd/blob/master/doc/ENVIRONMENT.md
+ https://github.com/systemd/systemd/blob/master/docs/ENVIRONMENT.md
* sd-daemon gained a new API sd_is_socket_sockaddr() for determining
whether a specific socket file descriptor matches a specified socket
projects / thirdparty / systemd.git / blobdiff