4.3 KiB
% DOCKER(1) Docker User Manuals % Docker Community % JUNE 2014
NAME
docker-update - Update configuration of one or more containers
SYNOPSIS
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...]
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. You can only update --kernel-memory on a stopped container or on a running container with kernel memory initialized.
OPTIONS
--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 on a running container if the container is started without kernel memory initialized, in this case, it can only be updated after it's stopped. The new setting takes effect when the container is 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).
EXAMPLES
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 --kernel-memory option. 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.
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.
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
container.
To update restart policy for one or more containers:
$ docker update --restart=on-failure:3 abebf7571666 hopeful_morse