Update configuration of one or more containers
$ docker update [OPTIONS] CONTAINER [CONTAINER...]
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.
docker container updatecommands are not supported for Windows containers.
For example uses of this command, refer to the examples section below.
||Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)|
||Limit CPU CFS (Completely Fair Scheduler) period|
||Limit CPU CFS (Completely Fair Scheduler) quota|
||Limit the CPU real-time period in microseconds|
||Limit the CPU real-time runtime in microseconds|
||CPU shares (relative weight)|
||Number of CPUs|
||CPUs in which to allow execution (0-3, 0,1)|
||MEMs in which to allow execution (0-3, 0,1)|
||Kernel memory limit|
||Memory soft limit|
||Swap limit equal to memory plus swap: '-1' to enable unlimited swap|
Tune container pids limit (set -1 for unlimited)
||Restart policy to apply when a container exits|
The following sections illustrate ways to use this command.
Update a container’s 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
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
You can update a container’s kernel memory limit using the
option. On kernel version older than 4.6, this option can be updated on a
running container only if the container was started with
If the container was started without
--kernel-memory you need to stop
the container before updating kernel memory.
--kernel-memoryoption 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
--kernel-memory the same way as other options.
Update a container’s restart policy
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
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
RestartPolicy are mutually exclusive for the