podman-update - Man Page
Update the configuration of a given container
Synopsis
podman update [options] container
podman container update [options] container
Description
Updates the configuration of an already existing container, allowing different resource limits to be set. The currently supported options are a subset of the podman create/run resource limit options.
Options
--blkio-weight=weight
Block IO relative weight. The weight is a value between 10 and 1000.
This option is not supported on cgroups V1 rootless systems.
--blkio-weight-device=device:weight
Block IO relative device weight.
--cpu-period=limit
Set the CPU period for the Completely Fair Scheduler (CFS), which is a duration in microseconds. Once the container's CPU quota is used up, it will not be scheduled to run until the current period ends. Defaults to 100000 microseconds.
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpu-quota=limit
Limit the CPU Completely Fair Scheduler (CFS) quota.
Limit the container's CPU usage. By default, containers run with the full CPU resource. The limit is a number in microseconds. If a number is provided, the container is allowed to use that much CPU time until the CPU period ends (controllable via --cpu-period).
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpu-rt-period=microseconds
Limit the CPU real-time period in microseconds.
Limit the container's Real Time CPU usage. This option tells the kernel to restrict the container's Real Time CPU usage to the period specified.
This option is only supported on cgroups V1 rootful systems.
--cpu-rt-runtime=microseconds
Limit the CPU real-time runtime in microseconds.
Limit the containers Real Time CPU usage. This option tells the kernel to limit the amount of time in a given CPU period Real Time tasks may consume. Ex: Period of 1,000,000us and Runtime of 950,000us means that this container can consume 95% of available CPU and leave the remaining 5% to normal priority tasks.
The sum of all runtimes across containers cannot exceed the amount allotted to the parent cgroup.
This option is only supported on cgroups V1 rootful systems.
--cpus=number
Number of CPUs. The default is 0.0 which means no limit. This is shorthand for --cpu-period and --cpu-quota, therefore the option cannot be specified with --cpu-period or --cpu-quota.
On some systems, changing the CPU limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpuset-cpus=number
CPUs in which to allow execution. Can be specified as a comma-separated list (e.g. 0,1), as a range (e.g. 0-3), or any combination thereof (e.g. 0-3,7,11-15).
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpuset-mems=nodes
Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.
If there are four memory nodes on the system (0-3), use --cpuset-mems=0,1 then processes in the container only uses memory from the first two memory nodes.
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--device-read-bps=path:rate
Limit read rate (in bytes per second) from a device (e.g. --device-read-bps=/dev/sda:1mb).
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--device-read-iops=path:rate
Limit read rate (in IO operations per second) from a device (e.g. --device-read-iops=/dev/sda:1000).
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--device-write-bps=path:rate
Limit write rate (in bytes per second) to a device (e.g. --device-write-bps=/dev/sda:1mb).
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--device-write-iops=path:rate
Limit write rate (in IO operations per second) to a device (e.g. --device-write-iops=/dev/sda:1000).
On some systems, changing the resource limits may not be allowed for non-root users. For more details, see https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-resource-limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--memory, -m=number[unit]
Memory limit. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes).
Allows the memory available to a container to be constrained. If the host supports swap memory, then the -m memory setting can be larger than physical RAM. If a limit of 0 is specified (not using -m), the container's memory is not limited. The actual limit may be rounded up to a multiple of the operating system's page size (the value is very large, that's millions of trillions).
This option is not supported on cgroups V1 rootless systems.
--memory-reservation=number[unit]
Memory soft limit. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes).
After setting memory reservation, when the system detects memory contention or low memory, containers are forced to restrict their consumption to their reservation. So always set the value below --memory, otherwise the hard limit takes precedence. By default, memory reservation is the same as memory limit.
This option is not supported on cgroups V1 rootless systems.
--memory-swap=number[unit]
A limit value equal to memory plus swap. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes).
Must be used with the -m (--memory) flag. The argument value must be larger than that of
-m (--memory) By default, it is set to double the value of --memory.
Set number to -1 to enable unlimited swap.
This option is not supported on cgroups V1 rootless systems.
--memory-swappiness=number
Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.
This flag is only supported on cgroups V1 rootful systems.
--pids-limit=limit
Tune the container's pids limit. Set to -1 to have unlimited pids for the container. The default is 2048 on systems that support "pids" cgroup controller.
--restart=policy
Restart policy to follow when containers exit. Restart policy does not take effect if a container is stopped via the podman kill or podman stop commands.
Valid policy values are:
- no : Do not restart containers on exit
- never : Synonym for no; do not restart containers on exit
- on-failure[:max_retries] : Restart containers when they exit with a non-zero exit code, retrying indefinitely or until the optional max_retries count is hit
- always : Restart containers when they exit, regardless of status, retrying indefinitely
- unless-stopped : Identical to always
Podman provides a systemd unit file, podman-restart.service, which restarts containers after a system reboot.
When running containers in systemd services, use the restart functionality provided by systemd. In other words, do not use this option in a container unit, instead set the Restart= systemd directive in the [Service] section. See podman-systemd.unit(5) and systemd.service(5).
EXAMPLEs
Update a container with a new cpu quota and period.
podman update --cpus=5 myCtr
Update a container with all available options for cgroups v2.
podman update --cpus 5 --cpuset-cpus 0 --cpu-shares 123 --cpuset-mems 0 --memory 1G --memory-swap 2G --memory-reservation 2G --blkio-weight-device /dev/zero:123 --blkio-weight 123 --device-read-bps /dev/zero:10mb --device-write-bps /dev/zero:10mb --device-read-iops /dev/zero:1000 --device-write-iops /dev/zero:1000 --pids-limit 123 ctrID
Update a container with all available options for cgroups v1.
podman update --cpus 5 --cpuset-cpus 0 --cpu-shares 123 --cpuset-mems 0 --memory 1G --memory-swap 2G --memory-reservation 2G --memory-swappiness 50 --pids-limit 123 ctrID
See Also
History
August 2022, Originally written by Charlie Doern cdoern@redhat.com ⟨mailto:cdoern@redhat.com⟩
Referenced By
podman(1), podman-container(1).
The man pages docker-container-update(1), docker-update(1) and podman-container-update(1) are aliases of podman-update(1).