DockerCLI/docs/reference/commandline/update.md

update

Update configuration of one or more containers

Aliases

docker container update, docker update

Options

Name	Type	Default	Description
--blkio-weight	uint16	0	Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)
--cpu-period	int64	0	Limit CPU CFS (Completely Fair Scheduler) period
--cpu-quota	int64	0	Limit CPU CFS (Completely Fair Scheduler) quota
--cpu-rt-period	int64	0	Limit the CPU real-time period in microseconds
--cpu-rt-runtime	int64	0	Limit the CPU real-time runtime in microseconds
-c, --cpu-shares	int64	0	CPU shares (relative weight)
--cpus	decimal		Number of CPUs
--cpuset-cpus	string		CPUs in which to allow execution (0-3, 0,1)
--cpuset-mems	string		MEMs in which to allow execution (0-3, 0,1)
-m, --memory	bytes	0	Memory limit
--memory-reservation	bytes	0	Memory soft limit
--memory-swap	bytes	0	Swap limit equal to memory plus swap: -1 to enable unlimited swap
--pids-limit	int64	0	Tune container pids limit (set -1 for unlimited)
--restart	string		Restart policy to apply when a container exits

Description

The docker update command dynamically updates container configuration. You can use this command to prevent containers from consuming too many resources from their Docker host. With a single command, you can place limits on a single container or on many. To specify more than one container, provide space-separated list of container names or IDs.

With the exception of the --kernel-memory option, you can specify these options on a running or a stopped container. On kernel version older than 4.6, you can only update --kernel-memory on a stopped container or on a running container with kernel memory initialized.

Warning

The docker update and docker container update commands are not supported for Windows containers. {: .warning }

Examples

The following sections illustrate ways to use this command.

Update a container's cpu-shares (--cpu-shares)

To limit a container's cpu-shares to 512, first identify the container name or ID. You can use docker ps to find these values. You can also use the ID returned from the docker run command. Then, do the following:

$ docker update --cpu-shares 512 abebf7571666

Update a container with cpu-shares and memory (-m, --memory)

To update multiple resource configurations for multiple containers:

$ docker update --cpu-shares 512 -m 300M abebf7571666 hopeful_morse

Update a container's kernel memory constraints (--kernel-memory)

You can update a container's kernel memory limit using the --kernel-memory option. On kernel version older than 4.6, this option can be updated on a running container only if the container was started with --kernel-memory. If the container was started without --kernel-memory you need to stop the container before updating kernel memory.

Note

The --kernel-memory option has been deprecated since Docker 20.10.

For example, if you started a container with this command:

$ docker run -dit --name test --kernel-memory 50M ubuntu bash

You can update kernel memory while the container is running:

$ docker update --kernel-memory 80M test

If you started a container without kernel memory initialized:

$ docker run -dit --name test2 --memory 300M ubuntu bash

Update kernel memory of running container test2 will fail. You need to stop the container before updating the --kernel-memory setting. The next time you start it, the container uses the new value.

Kernel version newer than (include) 4.6 does not have this limitation, you can use --kernel-memory the same way as other options.

Update a container's restart policy (--restart)

You can change a container's restart policy on a running container. The new restart policy takes effect instantly after you run docker update on a container.

To update restart policy for one or more containers:

$ docker update --restart=on-failure:3 abebf7571666 hopeful_morse

Note that if the container is started with "--rm" flag, you cannot update the restart policy for it. The AutoRemove and RestartPolicy are mutually exclusive for the container.