systemd.resource-controlsystemdsystemd.resource-control5systemd.resource-controlResource control unit settingsslice.slice,
scope.scope,
service.service,
socket.socket,
mount.mount,
swap.swapDescriptionUnit configuration files for services, slices, scopes, sockets, mount points, and swap devices share a subset
of configuration options for resource control of spawned processes. Internally, this relies on the Linux Control
Groups (cgroups) kernel concept for organizing processes in a hierarchical tree of named groups for the purpose of
resource management.This man page lists the configuration options shared by
those six unit types. See
systemd.unit5
for the common options of all unit configuration files, and
systemd.slice5,
systemd.scope5,
systemd.service5,
systemd.socket5,
systemd.mount5,
and
systemd.swap5
for more information on the specific unit configuration files. The
resource control configuration options are configured in the
[Slice], [Scope], [Service], [Socket], [Mount], or [Swap]
sections, depending on the unit type.In addition, options which control resources available to programs
executed by systemd are listed in
systemd.exec5.
Those options complement options listed here.See the New
Control Group Interfaces for an introduction on how to make
use of resource control APIs from programs.Implicit DependenciesThe following dependencies are implicitly added:Units with the Slice= setting set automatically acquire
Requires= and After= dependencies on the specified
slice unit.Unified and Legacy Control Group HierarchiesThe unified control group hierarchy is the new version of kernel control group interface, see
Control Groups v2.
Depending on the resource type, there are differences in resource control capabilities. Also, because of
interface changes, some resource types have separate set of options on the unified hierarchy.CPUCPUWeight= and StartupCPUWeight= replace
CPUShares= and StartupCPUShares=, respectively.The cpuacct controller does not exist separately on the unified hierarchy.MemoryMemoryMax= replaces MemoryLimit=. MemoryLow=
and MemoryHigh= are effective only on unified hierarchy.IOIO-prefixed settings are a superset of and replace
BlockIO-prefixed ones. On unified hierarchy, IO resource control also applies
to buffered writes.To ease the transition, there is best-effort translation between the two versions of settings. For each
controller, if any of the settings for the unified hierarchy are present, all settings for the legacy hierarchy are
ignored. If the resulting settings are for the other type of hierarchy, the configurations are translated before
application.Legacy control group hierarchy (see Control Groups version 1),
also called cgroup-v1, doesn't allow safe delegation of controllers to unprivileged processes. If the
system uses the legacy control group hierarchy, resource control is disabled for the systemd user
instance, see
systemd1.OptionsUnits of the types listed above can have settings
for resource control configuration:CPUAccounting=Turn on CPU usage accounting for this unit. Takes a
boolean argument. Note that turning on CPU accounting for
one unit will also implicitly turn it on for all units
contained in the same slice and for all its parent slices
and the units contained therein. The system default for this
setting may be controlled with
DefaultCPUAccounting= in
systemd-system.conf5.CPUWeight=weightStartupCPUWeight=weightAssign the specified CPU time weight to the processes executed, if the unified control group hierarchy
is used on the system. These options take an integer value and control the cpu.weight
control group attribute. The allowed range is 1 to 10000. Defaults to 100. For details about this control
group attribute, see Control Groups v2 and CFS Scheduler.
The available CPU time is split up among all units within one slice relative to their CPU time weight.While StartupCPUWeight= only applies to the startup phase of the system,
CPUWeight= applies to normal runtime of the system, and if the former is not set also to
the startup phase. Using StartupCPUWeight= allows prioritizing specific services at
boot-up differently than during normal runtime.These settings replace CPUShares= and StartupCPUShares=.CPUQuota=Assign the specified CPU time quota to the processes executed. Takes a percentage value, suffixed with
"%". The percentage specifies how much CPU time the unit shall get at maximum, relative to the total CPU time
available on one CPU. Use values > 100% for allotting CPU time on more than one CPU. This controls the
cpu.max attribute on the unified control group hierarchy and
cpu.cfs_quota_us on legacy. For details about these control group attributes, see Control Groups v2 and sched-bwc.txt.Example: CPUQuota=20% ensures that the executed processes will never get more than
20% CPU time on one CPU.CPUQuotaPeriodSec=Assign the duration over which the CPU time quota specified by CPUQuota= is measured.
Takes a time duration value in seconds, with an optional suffix such as "ms" for milliseconds (or "s" for seconds.)
The default setting is 100ms. The period is clamped to the range supported by the kernel, which is [1ms, 1000ms].
Additionally, the period is adjusted up so that the quota interval is also at least 1ms.
Setting CPUQuotaPeriodSec= to an empty value resets it to the default.This controls the second field of cpu.max attribute on the unified control group hierarchy
and cpu.cfs_period_us on legacy. For details about these control group attributes, see
Control Groups v2 and
CFS Scheduler.Example: CPUQuotaPeriodSec=10ms to request that the CPU quota is measured in periods of 10ms.AllowedCPUs=Restrict processes to be executed on specific CPUs. Takes a list of CPU indices or ranges separated by either
whitespace or commas. CPU ranges are specified by the lower and upper CPU indices separated by a dash.Setting AllowedCPUs= doesn't guarantee that all of the CPUs will be used by the processes
as it may be limited by parent units. The effective configuration is reported as EffectiveCPUs=.This setting is supported only with the unified control group hierarchy.AllowedMemoryNodes=Restrict processes to be executed on specific memory NUMA nodes. Takes a list of memory NUMA nodes indices
or ranges separated by either whitespace or commas. Memory NUMA nodes ranges are specified by the lower and upper
CPU indices separated by a dash.Setting AllowedMemoryNodes= doesn't guarantee that all of the memory NUMA nodes will
be used by the processes as it may be limited by parent units. The effective configuration is reported as
EffectiveMemoryNodes=.This setting is supported only with the unified control group hierarchy.MemoryAccounting=Turn on process and kernel memory accounting for this
unit. Takes a boolean argument. Note that turning on memory
accounting for one unit will also implicitly turn it on for
all units contained in the same slice and for all its parent
slices and the units contained therein. The system default
for this setting may be controlled with
DefaultMemoryAccounting= in
systemd-system.conf5.MemoryMin=bytesSpecify the memory usage protection of the executed processes in this unit. If the memory usages of
this unit and all its ancestors are below their minimum boundaries, this unit's memory won't be reclaimed.Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
percentage value may be specified, which is taken relative to the installed physical memory on the
system. If assigned the special value infinity, all available memory is protected, which may be
useful in order to always inherit all of the protection afforded by ancestors.
This controls the memory.min control group attribute. For details about this
control group attribute, see Memory Interface Files.This setting is supported only if the unified control group hierarchy is used and disables
MemoryLimit=.Units may have their children use a default memory.min value by specifying
DefaultMemoryMin=, which has the same semantics as MemoryMin=. This setting
does not affect memory.min in the unit itself.MemoryLow=bytesSpecify the best-effort memory usage protection of the executed processes in this unit. If the memory
usages of this unit and all its ancestors are below their low boundaries, this unit's memory won't be
reclaimed as long as memory can be reclaimed from unprotected units.Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
percentage value may be specified, which is taken relative to the installed physical memory on the
system. If assigned the special value infinity, all available memory is protected, which may be
useful in order to always inherit all of the protection afforded by ancestors.
This controls the memory.low control group attribute. For details about this
control group attribute, see Memory Interface Files.This setting is supported only if the unified control group hierarchy is used and disables
MemoryLimit=.Units may have their children use a default memory.low value by specifying
DefaultMemoryLow=, which has the same semantics as MemoryLow=. This setting
does not affect memory.low in the unit itself.MemoryHigh=bytesSpecify the throttling limit on memory usage of the executed processes in this unit. Memory usage may go
above the limit if unavoidable, but the processes are heavily slowed down and memory is taken away
aggressively in such cases. This is the main mechanism to control memory usage of a unit.Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
percentage value may be specified, which is taken relative to the installed physical memory on the
system. If assigned the
special value infinity, no memory throttling is applied. This controls the
memory.high control group attribute. For details about this control group attribute, see
Memory Interface Files.This setting is supported only if the unified control group hierarchy is used and disables
MemoryLimit=.MemoryMax=bytesSpecify the absolute limit on memory usage of the executed processes in this unit. If memory usage
cannot be contained under the limit, out-of-memory killer is invoked inside the unit. It is recommended to
use MemoryHigh= as the main control mechanism and use MemoryMax= as the
last line of defense.Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
percentage value may be specified, which is taken relative to the installed physical memory on the system. If
assigned the special value infinity, no memory limit is applied. This controls the
memory.max control group attribute. For details about this control group attribute, see
Memory Interface Files.This setting replaces MemoryLimit=.MemorySwapMax=bytesSpecify the absolute limit on swap usage of the executed processes in this unit.Takes a swap size in bytes. If the value is suffixed with K, M, G or T, the specified swap size is
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. If assigned the
special value infinity, no swap limit is applied. This controls the
memory.swap.max control group attribute. For details about this control group attribute,
see Memory Interface Files.This setting is supported only if the unified control group hierarchy is used and disables
MemoryLimit=.TasksAccounting=Turn on task accounting for this unit. Takes a
boolean argument. If enabled, the system manager will keep
track of the number of tasks in the unit. The number of
tasks accounted this way includes both kernel threads and
userspace processes, with each thread counting
individually. Note that turning on tasks accounting for one
unit will also implicitly turn it on for all units contained
in the same slice and for all its parent slices and the
units contained therein. The system default for this setting
may be controlled with
DefaultTasksAccounting= in
systemd-system.conf5.TasksMax=NSpecify the maximum number of tasks that may be created in the unit. This ensures that the number of
tasks accounted for the unit (see above) stays below a specific limit. This either takes an absolute number
of tasks or a percentage value that is taken relative to the configured maximum number of tasks on the
system. If assigned the special value infinity, no tasks limit is applied. This controls
the pids.max control group attribute. For details about this control group attribute, see
Process Number Controller.
The system default for this setting may be controlled with
DefaultTasksMax= in
systemd-system.conf5.IOAccounting=Turn on Block I/O accounting for this unit, if the unified control group hierarchy is used on the
system. Takes a boolean argument. Note that turning on block I/O accounting for one unit will also implicitly
turn it on for all units contained in the same slice and all for its parent slices and the units contained
therein. The system default for this setting may be controlled with DefaultIOAccounting=
in
systemd-system.conf5.This setting replaces BlockIOAccounting= and disables settings prefixed with
BlockIO or StartupBlockIO.IOWeight=weightStartupIOWeight=weightSet the default overall block I/O weight for the executed processes, if the unified control group
hierarchy is used on the system. Takes a single weight value (between 1 and 10000) to set the default block
I/O weight. This controls the io.weight control group attribute, which defaults to
100. For details about this control group attribute, see IO Interface Files.
The available I/O bandwidth is split up among all units within one slice relative to their block
I/O weight.While StartupIOWeight= only applies
to the startup phase of the system,
IOWeight= applies to the later runtime of
the system, and if the former is not set also to the startup
phase. This allows prioritizing specific services at boot-up
differently than during runtime.These settings replace BlockIOWeight= and StartupBlockIOWeight=
and disable settings prefixed with BlockIO or StartupBlockIO.IODeviceWeight=deviceweightSet the per-device overall block I/O weight for the executed processes, if the unified control group
hierarchy is used on the system. Takes a space-separated pair of a file path and a weight value to specify
the device specific weight value, between 1 and 10000. (Example: /dev/sda 1000). The file
path may be specified as path to a block device node or as any other file, in which case the backing block
device of the file system of the file is determined. This controls the io.weight control
group attribute, which defaults to 100. Use this option multiple times to set weights for multiple devices.
For details about this control group attribute, see IO Interface Files.This setting replaces BlockIODeviceWeight= and disables settings prefixed with
BlockIO or StartupBlockIO.The specified device node should reference a block device that has an I/O scheduler
associated, i.e. should not refer to partition or loopback block devices, but to the originating,
physical device. When a path to a regular file or directory is specified it is attempted to
discover the correct originating device backing the file system of the specified path. This works
correctly only for simpler cases, where the file system is directly placed on a partition or
physical block device, or where simple 1:1 encryption using dm-crypt/LUKS is used. This discovery
does not cover complex storage and in particular RAID and volume management storage devices.IOReadBandwidthMax=devicebytesIOWriteBandwidthMax=devicebytesSet the per-device overall block I/O bandwidth maximum limit for the executed processes, if the unified
control group hierarchy is used on the system. This limit is not work-conserving and the executed processes
are not allowed to use more even if the device has idle capacity. Takes a space-separated pair of a file
path and a bandwidth value (in bytes per second) to specify the device specific bandwidth. The file path may
be a path to a block device node, or as any other file in which case the backing block device of the file
system of the file is used. If the bandwidth is suffixed with K, M, G, or T, the specified bandwidth is
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes, respectively, to the base of 1000. (Example:
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 5M"). This controls the io.max control
group attributes. Use this option multiple times to set bandwidth limits for multiple devices. For details
about this control group attribute, see IO Interface Files.
These settings replace BlockIOReadBandwidth= and
BlockIOWriteBandwidth= and disable settings prefixed with BlockIO or
StartupBlockIO.Similar restrictions on block device discovery as for IODeviceWeight= apply, see above.IOReadIOPSMax=deviceIOPSIOWriteIOPSMax=deviceIOPSSet the per-device overall block I/O IOs-Per-Second maximum limit for the executed processes, if the
unified control group hierarchy is used on the system. This limit is not work-conserving and the executed
processes are not allowed to use more even if the device has idle capacity. Takes a space-separated pair of
a file path and an IOPS value to specify the device specific IOPS. The file path may be a path to a block
device node, or as any other file in which case the backing block device of the file system of the file is
used. If the IOPS is suffixed with K, M, G, or T, the specified IOPS is parsed as KiloIOPS, MegaIOPS,
GigaIOPS, or TeraIOPS, respectively, to the base of 1000. (Example:
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 1K"). This controls the io.max control
group attributes. Use this option multiple times to set IOPS limits for multiple devices. For details about
this control group attribute, see IO Interface Files.
These settings are supported only if the unified control group hierarchy is used and disable settings
prefixed with BlockIO or StartupBlockIO.Similar restrictions on block device discovery as for IODeviceWeight= apply, see above.IODeviceLatencyTargetSec=devicetargetSet the per-device average target I/O latency for the executed processes, if the unified control group
hierarchy is used on the system. Takes a file path and a timespan separated by a space to specify
the device specific latency target. (Example: "/dev/sda 25ms"). The file path may be specified
as path to a block device node or as any other file, in which case the backing block device of the file
system of the file is determined. This controls the io.latency control group
attribute. Use this option multiple times to set latency target for multiple devices. For details about this
control group attribute, see IO Interface Files.Implies IOAccounting=yes.These settings are supported only if the unified control group hierarchy is used.Similar restrictions on block device discovery as for IODeviceWeight= apply, see above.IPAccounting=Takes a boolean argument. If true, turns on IPv4 and IPv6 network traffic accounting for packets sent
or received by the unit. When this option is turned on, all IPv4 and IPv6 sockets created by any process of
the unit are accounted for.When this option is used in socket units, it applies to all IPv4 and IPv6 sockets
associated with it (including both listening and connection sockets where this applies). Note that for
socket-activated services, this configuration setting and the accounting data of the service unit and the
socket unit are kept separate, and displayed separately. No propagation of the setting and the collected
statistics is done, in either direction. Moreover, any traffic sent or received on any of the socket unit's
sockets is accounted to the socket unit — and never to the service unit it might have activated, even if the
socket is used by it.The system default for this setting may be controlled with DefaultIPAccounting= in
systemd-system.conf5.IPAddressAllow=ADDRESS[/PREFIXLENGTH]…IPAddressDeny=ADDRESS[/PREFIXLENGTH]…Turn on network traffic filtering for IP packets sent and received over
AF_INET and AF_INET6 sockets. Both directives take a
space separated list of IPv4 or IPv6 addresses, each optionally suffixed with an address prefix
length in bits after a / character. If the suffix is omitted, the address is
considered a host address, i.e. the filter covers the whole address (32 bits for IPv4, 128 bits for
IPv6).The access lists configured with this option are applied to all sockets created by processes
of this unit (or in the case of socket units, associated with it). The lists are implicitly
combined with any lists configured for any of the parent slice units this unit might be a member
of. By default both access lists are empty. Both ingress and egress traffic is filtered by these
settings. In case of ingress traffic the source IP address is checked against these access lists,
in case of egress traffic the destination IP address is checked. The following rules are applied in
turn:Access is granted when the checked IP address matches an entry in the
IPAddressAllow= list.Otherwise, access is denied when the checked IP address matches an entry in the
IPAddressDeny= list.Otherwise, access is granted.In order to implement a whitelisting IP firewall, it is recommended to use a
IPAddressDeny=any setting on an upper-level slice unit (such as the
root slice -.slice or the slice containing all system services
system.slice – see
systemd.special7 for
details on these slice units), plus individual per-service IPAddressAllow= lines
permitting network access to relevant services, and only them.Note that for socket-activated services, the IP access list configured on the socket unit
applies to all sockets associated with it directly, but not to any sockets created by the
ultimately activated services for it. Conversely, the IP access list configured for the service is
not applied to any sockets passed into the service via socket activation. Thus, it is usually a
good idea to replicate the IP access lists on both the socket and the service unit. Nevertheless,
it may make sense to maintain one list more open and the other one more restricted, depending on
the usecase.If these settings are used multiple times in the same unit the specified lists are combined. If an
empty string is assigned to these settings the specific access list is reset and all previous settings undone.In place of explicit IPv4 or IPv6 address and prefix length specifications a small set of symbolic
names may be used. The following names are defined:
Special address/network namesSymbolic NameDefinitionMeaningany0.0.0.0/0 ::/0Any hostlocalhost127.0.0.0/8 ::1/128All addresses on the local loopbacklink-local169.254.0.0/16 fe80::/64All link-local IP addressesmulticast224.0.0.0/4 ff00::/8All IP multicasting addresses
Note that these settings might not be supported on some systems (for example if eBPF control group
support is not enabled in the underlying kernel or container manager). These settings will have no effect in
that case. If compatibility with such systems is desired it is hence recommended to not exclusively rely on
them for IP security.IPIngressFilterPath=BPF_FS_PROGRAMM_PATHIPEgressFilterPath=BPF_FS_PROGRAMM_PATHAdd custom network traffic filters implemented as BPF programs, applying to all IP packets
sent and received over AF_INET and AF_INET6 sockets.
Takes an absolute path to a pinned BPF program in the BPF virtual filesystem (/sys/fs/bpf/).
The filters configured with this option are applied to all sockets created by processes
of this unit (or in the case of socket units, associated with it). The filters are loaded in addition
to filters any of the parent slice units this unit might be a member of as well as any
IPAddressAllow= and IPAddressDeny= filters in any of these units.
By default there are no filters specified.If these settings are used multiple times in the same unit all the specified programs are attached. If an
empty string is assigned to these settings the program list is reset and all previous specified programs ignored.Note that for socket-activated services, the IP filter programs configured on the socket unit apply to
all sockets associated with it directly, but not to any sockets created by the ultimately activated services
for it. Conversely, the IP filter programs configured for the service are not applied to any sockets passed into
the service via socket activation. Thus, it is usually a good idea, to replicate the IP filter programs on both
the socket and the service unit, however it often makes sense to maintain one configuration more open and the other
one more restricted, depending on the usecase.Note that these settings might not be supported on some systems (for example if eBPF control group
support is not enabled in the underlying kernel or container manager). These settings will fail the service in
that case. If compatibility with such systems is desired it is hence recommended to attach your filter manually
(requires Delegate=yes) instead of using this setting.DeviceAllow=Control access to specific device nodes by the executed processes. Takes two space-separated
strings: a device node specifier followed by a combination of r,
w, m to control reading,
writing, or creation of the specific device node(s) by the unit
(mknod), respectively. On cgroup-v1 this controls the
devices.allow control group attribute. For details about this control group
attribute, see Device Whitelist Controller.
In the unified cgroup hierarchy this functionality is implemented using eBPF filtering.The device node specifier is either a path to a device node in the file system, starting with
/dev/, or a string starting with either char- or
block- followed by a device group name, as listed in
/proc/devices. The latter is useful to whitelist all current and future
devices belonging to a specific device group at once. The device group is matched according to
filename globbing rules, you may hence use the * and ?
wildcards. (Note that such globbing wildcards are not available for device node path
specifications!) In order to match device nodes by numeric major/minor, use device node paths in
the /dev/char/ and /dev/block/ directories. However,
matching devices by major/minor is generally not recommended as assignments are neither stable nor
portable between systems or different kernel versions.Examples: /dev/sda5 is a path to a device node, referring to an ATA or
SCSI block device. char-pts and char-alsa are specifiers for
all pseudo TTYs and all ALSA sound devices, respectively. char-cpu/* is a
specifier matching all CPU related device groups.Note that whitelists defined this way should only reference device groups which are
resolvable at the time the unit is started. Any device groups not resolvable then are not added to
the device whitelist. In order to work around this limitation, consider extending service units
with a pair of After=modprobe@xyz.service and
Wants=modprobe@xyz.service lines that load the necessary kernel module
implementing the device group if missing.
Example: …
[Unit]
Wants=modprobe@loop.service
After=modprobe@loop.service
[Service]
DeviceAllow=block-loop
DeviceAllow=/dev/loop-control
…DevicePolicy=auto|closed|strict
Control the policy for allowing device access:
means to only allow types of access that are
explicitly specified.in addition, allows access to standard pseudo
devices including
/dev/null,
/dev/zero,
/dev/full,
/dev/random, and
/dev/urandom.
in addition, allows access to all devices if no
explicit DeviceAllow= is present.
This is the default.
Slice=The name of the slice unit to place the unit
in. Defaults to system.slice for all
non-instantiated units of all unit types (except for slice
units themselves see below). Instance units are by default
placed in a subslice of system.slice
that is named after the template name.This option may be used to arrange systemd units in a
hierarchy of slices each of which might have resource
settings applied.For units of type slice, the only accepted value for
this setting is the parent slice. Since the name of a slice
unit implies the parent slice, it is hence redundant to ever
set this parameter directly for slice units.Special care should be taken when relying on the default slice assignment in templated service units
that have DefaultDependencies=no set, see
systemd.service5, section
"Default Dependencies" for details.Delegate=Turns on delegation of further resource control partitioning to processes of the unit. Units where this
is enabled may create and manage their own private subhierarchy of control groups below the control group of
the unit itself. For unprivileged services (i.e. those using the User= setting) the unit's
control group will be made accessible to the relevant user. When enabled the service manager will refrain
from manipulating control groups or moving processes below the unit's control group, so that a clear concept
of ownership is established: the control group tree above the unit's control group (i.e. towards the root
control group) is owned and managed by the service manager of the host, while the control group tree below
the unit's control group is owned and managed by the unit itself. Takes either a boolean argument or a list
of control group controller names. If true, delegation is turned on, and all supported controllers are
enabled for the unit, making them available to the unit's processes for management. If false, delegation is
turned off entirely (and no additional controllers are enabled). If set to a list of controllers, delegation
is turned on, and the specified controllers are enabled for the unit. Note that additional controllers than
the ones specified might be made available as well, depending on configuration of the containing slice unit
or other units contained in it. Note that assigning the empty string will enable delegation, but reset the
list of controllers, all assignments prior to this will have no effect. Defaults to false.Note that controller delegation to less privileged code is only safe on the unified control group
hierarchy. Accordingly, access to the specified controllers will not be granted to unprivileged services on
the legacy hierarchy, even when requested.Not all of these controllers are available on all kernels however, and some are
specific to the unified hierarchy while others are specific to the legacy hierarchy. Also note that the
kernel might support further controllers, which aren't covered here yet as delegation is either not supported
at all for them or not defined cleanly.For further details on the delegation model consult Control Group APIs and Delegation.DisableControllers=Disables controllers from being enabled for a unit's children. If a controller listed is already in use
in its subtree, the controller will be removed from the subtree. This can be used to avoid child units being
able to implicitly or explicitly enable a controller. Defaults to not disabling any controllers.It may not be possible to successfully disable a controller if the unit or any child of the unit in
question delegates controllers to its children, as any delegated subtree of the cgroup hierarchy is unmanaged
by systemd.Multiple controllers may be specified, separated by spaces. You may also pass
DisableControllers= multiple times, in which case each new instance adds another controller
to disable. Passing DisableControllers= by itself with no controller name present resets
the disabled controller list.Deprecated OptionsThe following options are deprecated. Use the indicated superseding options instead:CPUShares=weightStartupCPUShares=weightAssign the specified CPU time share weight to the processes executed. These options take an integer
value and control the cpu.shares control group attribute. The allowed range is 2 to
262144. Defaults to 1024. For details about this control group attribute, see CFS Scheduler.
The available CPU time is split up among all units within one slice relative to their CPU time share
weight.While StartupCPUShares= only applies to the startup phase of the system,
CPUShares= applies to normal runtime of the system, and if the former is not set also to
the startup phase. Using StartupCPUShares= allows prioritizing specific services at
boot-up differently than during normal runtime.Implies CPUAccounting=yes.These settings are deprecated. Use CPUWeight= and
StartupCPUWeight= instead.MemoryLimit=bytesSpecify the limit on maximum memory usage of the executed processes. The limit specifies how much
process and kernel memory can be used by tasks in this unit. Takes a memory size in bytes. If the value is
suffixed with K, M, G or T, the specified memory size is parsed as Kilobytes, Megabytes, Gigabytes, or
Terabytes (with the base 1024), respectively. Alternatively, a percentage value may be specified, which is
taken relative to the installed physical memory on the system. If assigned the special value
infinity, no memory limit is applied. This controls the
memory.limit_in_bytes control group attribute. For details about this control group
attribute, see Memory Resource Controller.Implies MemoryAccounting=yes.This setting is deprecated. Use MemoryMax= instead.BlockIOAccounting=Turn on Block I/O accounting for this unit, if the legacy control group hierarchy is used on the
system. Takes a boolean argument. Note that turning on block I/O accounting for one unit will also implicitly
turn it on for all units contained in the same slice and all for its parent slices and the units contained
therein. The system default for this setting may be controlled with
DefaultBlockIOAccounting= in
systemd-system.conf5.This setting is deprecated. Use IOAccounting= instead.BlockIOWeight=weightStartupBlockIOWeight=weightSet the default overall block I/O weight for the executed processes, if the legacy control
group hierarchy is used on the system. Takes a single weight value (between 10 and 1000) to set the default
block I/O weight. This controls the blkio.weight control group attribute, which defaults to
500. For details about this control group attribute, see Block IO Controller.
The available I/O bandwidth is split up among all units within one slice relative to their block I/O
weight.While StartupBlockIOWeight= only
applies to the startup phase of the system,
BlockIOWeight= applies to the later runtime
of the system, and if the former is not set also to the
startup phase. This allows prioritizing specific services at
boot-up differently than during runtime.Implies
BlockIOAccounting=yes.These settings are deprecated. Use IOWeight= and StartupIOWeight=
instead.BlockIODeviceWeight=deviceweightSet the per-device overall block I/O weight for the executed processes, if the legacy control group
hierarchy is used on the system. Takes a space-separated pair of a file path and a weight value to specify
the device specific weight value, between 10 and 1000. (Example: "/dev/sda 500"). The file path may be
specified as path to a block device node or as any other file, in which case the backing block device of the
file system of the file is determined. This controls the blkio.weight_device control group
attribute, which defaults to 1000. Use this option multiple times to set weights for multiple devices. For
details about this control group attribute, see Block IO Controller.Implies
BlockIOAccounting=yes.This setting is deprecated. Use IODeviceWeight= instead.BlockIOReadBandwidth=devicebytesBlockIOWriteBandwidth=devicebytesSet the per-device overall block I/O bandwidth limit for the executed processes, if the legacy control
group hierarchy is used on the system. Takes a space-separated pair of a file path and a bandwidth value (in
bytes per second) to specify the device specific bandwidth. The file path may be a path to a block device
node, or as any other file in which case the backing block device of the file system of the file is used. If
the bandwidth is suffixed with K, M, G, or T, the specified bandwidth is parsed as Kilobytes, Megabytes,
Gigabytes, or Terabytes, respectively, to the base of 1000. (Example:
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 5M"). This controls the
blkio.throttle.read_bps_device and blkio.throttle.write_bps_device
control group attributes. Use this option multiple times to set bandwidth limits for multiple devices. For
details about these control group attributes, see Block IO Controller.
Implies
BlockIOAccounting=yes.These settings are deprecated. Use IOReadBandwidthMax= and
IOWriteBandwidthMax= instead.See Alsosystemd1,
systemd-system.conf5,
systemd.unit5,
systemd.service5,
systemd.slice5,
systemd.scope5,
systemd.socket5,
systemd.mount5,
systemd.swap5,
systemd.exec5,
systemd.directives7,
systemd.special7,
The documentation for control groups and specific controllers in the Linux kernel:
Control Groups v2.