Vendor Class Identifier be used by DHCP clients to identify
their vendor type and configuration. When using this option,
vendors can define their own specific identifier values, such
as to convey a particular hardware or operating system
configuration or other identifying information.
Vendor-specified DHCP options—features that let administrators assign
separate options to clients with similar configuration requirements.
For example, if DHCP-aware clients for example we want to separate
different gateway and option for different set of people
(dev/test/hr/finance) in a org or devices for example web/database
servers or let's say in a embedded device etc and require a different
default gateway or DNS server than the rest of clients.
Now route metric can be configuted via conf file:
example conf:
[Match]
Name=em1
[Route]
Gateway=192.168.1.12
Metric=10
Test:
ip route output
default via 192.168.1.12 dev em1 metric 10
[tomegun: squash TODO update and reword man page a bit]
Turns out, making strings shell-proof is harder than expected:
# machinectl set-hostname "foo|poweroff" && . /etc/machine-info
(This could be simplified by quoting *and* escaping all characters,
which is harmless in shell but unnecessary.)
We already encourage upstreams to keep the default configuration
separate from user customizations for software that is installed in
the system location. Let's allow that separation also for software
that is installed in the home directory.
Some discussion:
http://thread.gmane.org/gmane.comp.sysutils.systemd.devel/19627
It is already in nodist_systemunit_DATA and if it is
shipped, it contains the hardcoded path to systemctl
which will cause it to fail to start when
rootprefix != prefix and rootbindir != bindir.
This reverts commit 0c26bfc3d2.
src/core/org.freedesktop.systemd1.policy.in.in depends on values which
are specified at configure time, so we cannot ship the corresponding
policy file in the tarball.
Since we need to regenerate one policy file, we might as well generate
them all.
A call to sd_event_source_set_io_events() skipps calling into the kernel
if the new event-mask matches the old one. This is safe for
level-triggered sources as the kernel moves them onto the ready-list
automatically if events change. However, edge-triggered sources might not
be on the ready-list even though events are present.
A call to sd_event_source_set_io_events() with EPOLLET set might thus be
used to just move the io-source onto the ready-list so the next poll
will return it again. This is very useful to avoid starvation in
priority-based event queues.
Imagine a read() loop on an edge-triggered fd. If we cannot read data fast
enough to drain the receive queue, we might decide to skip reading for now
and schedule it for later. On edge-triggered io-sources we have to make
sure it's put on the ready-list so the next dispatch-round will return it
again if it's still the highest priority task. We could make sd-event
handle edge-triggered sources directly and allow marking them ready again.
However, it's much simpler to let the kernel do that for now via
EPOLL_CTL_MOD.
The check only cares about whether the module is installed, not enabled.
But installation we should know anyway, after all we ship the module
with systemd these days...
An administrator might want to block a certain sysusers config file from
being executed, e.g. to block the creation of a certain user.
Only a relatively short description is added in the man page, since
overrides should be relatively rare.
Tom Gundersen