systemd是一个init程序。根据之前 Upstart的一些介绍大家应该简要了解了传统Sysvinit系统的不足之处。不过，这次的systemd的设计思想更为超前，也可以说是借鉴了OSX上launchd的思路。
systemd 219 发布，此版本包括大量的改进，特别是容器，btrfs，hookup 和网络模块，同时也有大量的 bug 修复，Enjoy！
此版本现已提供下载。
注意，此版本还未提供在 Fedora F22/F23。
更新内容：
* Introduce a new API "sd-hwdb.h" for querying the hardware
metadata database.
* When any of systemd's tools copies files (for example due to
tmpfiles' C lines) a btrfs reflink will attempted first,
before bytewise copying is done.
* systemd-nspawn gained a new --ephemeral switch.
* systemd-nspawn gained a new --template= switch.
* When a .mount unit refers to a mount point on which multiple
mounts are stacked, and the .mount unit is stopped all of
the stacked mount points will now be unmounted until no
mount point remains.
* systemd now has an explicit notion of supported and
unsupported unit types.
* machinectl gained support for two new "copy-from" and
"copy-to" commands for copying files from a running
container to the host or vice versa.
* machinectl gained support for a new "bind" command to bind
mount host directories into local containers. This is
currently only supported for nspawn containers.
* networkd gained support for configuring bridge forwarding
database entries (fdb) from .network files.
* A new tiny daemon "systemd-importd" has been added that can
download container images in tar, raw, qcow2 or dkr formats,
and make them available locally in /var/lib/machines, so
that they can run as nspawn containers. The daemon can GPG
verify the downloads (not supported for dkr, since it has no
provisions for verifying downloads).
* machinectl is now able to list container images found in
/var/lib/machines, along with some metadata about sizes of
disk and similar.
* machinectl is now able to clone container images
efficiently, if the underlying file system (btrfs) supports
it, with the new "machinectl list-images" command.
* networkd gained support for collecting LLDP network
announcements, from hardware that supports this. This is
shown in networkctl output.
* systemd-run gained support for a new -t (--pty) switch for
invoking a binary on a pty whose input and output is
connected to the invoking terminal.
* tmpfiles gained support for a new "v" line type for creating
btrfs subvolumes.
* The directory /var/lib/containers/ has been deprecated and
been replaced by /var/lib/machines.
* systemd-nspawn when invoked with -M but without --directory=
or --image= is now capable of searching for the container
root directory, subvolume or disk image automatically, in
/var/lib/machines.
* A new machines.target unit has been introduced that is
supposed to group all containers/VMs invoked as services on
the system.
* machinectl gained a new "start" command, for invoking a
container as a service.
* systemd-nspawn will now mount most of the cgroupfs tree
read-only into each container, with the exception of the
container's own subtree in the name=systemd hierarchy.
* journald now sets the special FS_NOCOW file flag for its
journal files.
* When journald detects that journal files it is writing to
have been deleted it will immediately start new journal
files.
* systemd now provides a way to store file descriptors
per-service in PID 1.
* The default TERM variable to use for units connected to a
terminal, when no other value is explicitly is set is now
vt220 rather than vt102. This should be fairly safe still,
but allows PgUp/PgDn work.
* The /etc/crypttab option header= as known from Debian is now
supported.
* "loginctl user-status" and "loginctl session-status" will
now show the last 10 lines of log messages of the
user/session following the status output. Similar,
"machinectl status" will show the last 10 log lines
associated with a virtual machine or container
service.
* "loginctl session-status" without further argument will now
show the status of the session of the caller.
* An X11 session scriptlet is now shipped that uploads
$DISPLAY and $XAUTHORITY into the environment of the systemd
--user daemon if a session begins.
* Generators are now subject to masking via /etc and /run, the
same way as unit files.
* networkd .network files gained support for configuring
per-link IPv4/IPv6 packet forwarding as well as IPv4
masquerading.
* systemd-nspawn gained the --port= (-p) switch to expose TCP
or UDP posts of a container on the host.
* systemd-nspawn's --network-veth switch now gained a short
version "-n", since with the changes above it is now truly
useful out-of-the-box.
* systemd-nspawn will now maintain a per-image R/W lock, to
ensure that the same image is not started more than once
writable. (It's OK to run an image multiple times
simultaneously in read-only mode.)
* systemd-nspawn's --image= option is now capable of
dissecting and booting MBR and GPT disk images that contain
only a single active Linux partition.
* In addition to collecting mouse dpi data in the udev
hardware database, there's now support for collecting angle
information for mouse scroll wheels.
* udev's input_id built-in will now also collect touch screen
dimension data and attach it to probed devices.
* /etc/os-release gained support for a Distribution Privacy
Policy link field.
* networkd gained support for creating "ipvlan", "gretap",
"ip6gre", "ip6gretap" and "ip6tnl" network devices.
* systemd-tmpfiles gained support for "a" lines for setting
ACLs on files.
* systemd-nspawn will now mount /tmp in the container to
tmpfs, automatically.
* systemd now exposes the memory.usage_in_bytes cgroup
attribute and shows it for each service in the "systemctl
status" output, if available.
* When the user presses Ctrl-Alt-Del more than 7x within 2s an
immediate reboot is triggered.
* A .device unit for an optical block device will now be
considered active only when a medium is in the drive.
* networkd-wait-online now has support for waiting for
specific interfaces only (with globbing), and for giving up
after a configurable timeout.
* networkd now exits when idle. It will be automatically
restarted as soon as interfaces show up, are removed or
change state.
* networkd may now configure IPv6 link-local addressing in
addition to IPv4 link-local addressing.
* The IPv6 "token" for use in SLAAC may now be configured for
each .network interface in networkd.
* Routes configured with networkd may now be assigned a scope
in .network files.
* networkd's [Match] sections now support globbing and lists
of multiple space-separated matches per item.
更多更新内容请看发行说明。
软件详情：http://lists.freedesktop.org/archives/systemd-devel/2015-February/028447.html
下载地址：http://www.freedesktop.org/software/systemd/systemd-219.tar.xz
来自:开源中国社区
