For some certification, it should not be possible to reboot the machine through ctrl-alt-delete. Currently we suggest our customers to mask the ctrl-alt-delete target, but that is obviously not enough.
Patching the keymaps to disable that is really not a way to go for them, because the settings need to be easily checked by some SCAP tools.
As it turns out 512 is max number of tasks per service is hit by too many
applications, hence let's bump it a bit, and make it relative to the system's
maximum number of PIDs. With this change the new default is 15%. At the
kernel's default pids_max value of 32768 this translates to 4915. At machined's
default TasksMax= setting of 16384 this translates to 2457.
Why 15%? Because it sounds like a round number and is close enough to 4096
which I was going for, i.e. an eight-fold increase over the old 512
Summary:
| on the host | in a container
old default | 512 | 512
new default | 4915 | 2457
On the unified hierarchy, blkio controller is renamed to io and the interface
is changed significantly.
* blkio.weight and blkio.weight_device are consolidated into io.weight which
uses the standardized weight range [1, 10000] with 100 as the default value.
* blkio.throttle.{read|write}_{bps|iops}_device are consolidated into io.max.
Expansion of throttling features is being worked on to support
work-conserving absolute limits (io.low and io.high).
* All stats are consolidated into io.stats.
This patchset adds support for the new interface. As the interface has been
revamped and new features are expected to be added, it seems best to treat it
as a separate controller rather than trying to expand the blkio settings
although we might add automatic translation if only blkio settings are
specified.
* io.weight handling is mostly identical to blkio.weight[_device] handling
except that the weight range is different.
* Both read and write bandwidth settings are consolidated into
CGroupIODeviceLimit which describes all limits applicable to the device.
This makes it less painful to add new limits.
* "max" can be used to specify the maximum limit which is equivalent to no
config for max limits and treated as such. If a given CGroupIODeviceLimit
doesn't contain any non-default configs, the config struct is discarded once
the no limit config is applied to cgroup.
* lookup_blkio_device() is renamed to lookup_block_device().
Signed-off-by: Tejun Heo <htejun@fb.com>
We generally follow the rule that for time settings we suffix the setting name
with "Sec" to indicate the default unit if none is specified. The only
exception was the rate limiting interval settings. Fix this, and keep the old
names for compatibility.
Do the same for journald's RateLimitInterval= setting
This introduces a new systemd.crash_reboot=1 kernel command line option
that triggers a reboot after crashing.
This also cleans up crash VT handling. Specifically, it cleans up the
configuration setting, to be between 1..63 or a boolean. This is to
replace the previous logic where "-1" meant disabled. We continue to
accept that setting, but only document the boolean syntax instead.
This also brings the documentation of the default settings in sync with
what actually happens.
The CrashChVT= configuration file setting is renamed to CrashChangeVT=,
following our usual logic of not abbreviating unnecessarily. The old
setting stays support for compat reasons.
Fixes#1300
For daemons which have a main configuration file, there's
little reason for the administrator to use configuration snippets.
They are useful for packagers which need to override settings, but
we shouldn't advertise that as the main way of configuring those
services.
https://bugs.freedesktop.org/show_bug.cgi?id=89397
The system start timeout as previously implemented would get confused by
long-running services that are included in the initial system startup
transaction for example by being cron-job-like long-running services
triggered immediately at boot. Such long-running jobs would be subject
to the default 15min timeout, esily triggering it.
Hence, remove this again. In a subsequent commit, introduce per-target
job timeouts instead, that allow us to control these timeouts more
finegrained.
When this system-wide start-up timeout is hit we execute one of the
failure actions already implemented for services that fail.
This should not only be useful on embedded devices, but also on laptops
which have the power-button reachable when the lid is closed. This
devices, when in a backpack might get powered on by accident due to the
easily reachable power button. We want to make sure that the system
turns itself off if it starts up due this after a while.
When the system manages to fully start-up logind will suspend the
machine by default if the lid is closed. However, in some cases we don't
even get as far as logind, and the boot hangs much earlier, for example
because we ask for a LUKS password that nobody ever enters.
Yeah, this is a real-life problem on my Yoga 13, which has one of those
easily accessible power buttons, even if the device is closed.
Only accept cpu quota values in percentages, get rid of period
definition.
It's not clear whether the CFS period controllable per-cgroup even has a
future in the kernel, hence let's simplify all this, hardcode the period
to 100ms and only accept percentage based quota values.
This is useful to prohibit execution of non-native processes on systems,
for example 32bit binaries on 64bit systems, this lowering the attack
service on incorrect syscall and ioctl 32→64bit mappings.
This complements existing functionality of setting variables
through 'systemctl set-environment', the kernel command line,
and through normal environment variables for systemd in session
mode.
After talking to the cgroup kernel folks at LPC we came to the
conclusion that it is probably a good idea to mount all CPU related
resp. all network related cgroup controllers together, both because they
are good defaults for admins and because this might prepare
for eventual kernel cleanups where the ability to mount them separately
is removed.
This option never made much sense. It was originally intended to make
sure that the usual startup output of sysv scripts goes to the terminal.
However, since SysV scripts started from a terminal would not output to
that terminal, but rather /dev/console this effect was more often than
not actually taking place. Nowadays systemd has much nicer boot time
status output than SysV which makes the sysv output redundant. Finally,
all output of services goes to the journal anyway, and is not lost.
Hence, let's drop this option, and simplify things a bit.
This also ensures that caps dropped from the bounding set are also
dropped from the inheritable set, to be extra-secure. Usually that should
change very little though as the inheritable set is empty for all our uses
anyway.
The ability to set MountAuto=no and SwapAuto=no was useful during the
adoption phase of systemd, so that distributions could stick to their
classic mount scripts a bit longer. It is about time to get rid of it
now.
