% DOCKER(1) Docker User Manuals % Docker Community % JUNE 2014
docker-update - Update configuration of one or more containers
docker update [--blkio-weight[=[BLKIO-WEIGHT]]] [--cpu-shares[=0]] [--cpu-period[=0]] [--cpu-quota[=0]] [--cpuset-cpus[=CPUSET-CPUS]] [--cpuset-mems[=CPUSET-MEMS]] [--help] [--kernel-memory[=KERNEL-MEMORY]] [-m|--memory[=MEMORY]] [--memory-reservation[=MEMORY-RESERVATION]] [--memory-swap[=MEMORY-SWAP]] [--restart[=""]] 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 value, you can specify these options on a running or a stopped container. You can only update
--kernel-memory on a stopped container. When you run
docker update on stopped container, the next time you restart it, the container uses those values.
Another configuration you can change with this command is restart policy, new restart policy will take effect instantly after you run
docker update on a container.
--blkio-weight=0 Block IO weight (relative weight) accepts a weight value between 10 and 1000.
--cpu-shares=0 CPU shares (relative weight)
--cpu-period=0 Limit the CPU CFS (Completely Fair Scheduler) period
--cpu-quota=0 Limit the CPU CFS (Completely Fair Scheduler) quota
--cpuset-cpus="" CPUs in which to allow execution (0-3, 0,1)
--cpuset-mems="" Memory nodes(MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.
--help Print usage statement
--kernel-memory="" Kernel memory limit (format:
<number>[<unit>], where unit = b, k, m or g)
Note that you can not update kernel memory to a running container, it can only be updated to a stopped container, and affect after it's started.
-m, --memory="" Memory limit (format: , where unit = b, k, m or g)
--memory-reservation="" Memory soft limit (format: , where unit = b, k, m or g)
--memory-swap="" Total memory limit (memory + swap)
--restart="" Restart policy to apply when a container exits (no, on-failure[:max-retry], always, unless-stopped).
The following sections illustrate ways to use this command.
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
To update multiple resource configurations for multiple containers:
$ docker update --cpu-shares 512 -m 300M abebf7571666 hopeful_morse
To update restart policy for one or more containers:
$ docker update --restart=on-failure:3 abebf7571666 hopeful_morse