The docker update command dynamically updates container configuration. You can use this command to prevent containers from consuming too many resources such as CPU and memory from their Docker host. With a single command, you can place limits on a single container or on many.
Notes
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.
The docker update command dynamically updates container configuration. You can use this command to prevent containers from consuming too many resources such as CPU and memory from their Docker host. With a single command, you can place limits on a single container or on many.
Notes
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.
You can use “docker container update” instead of “docker update” as well.
Docker update command Example
docker update command Example
Update a container’s cpu-shares
$ docker update --cpu-shares 512 abebf7571666
Update a container with cpu-shares and memory
$ docker update --cpu-shares 512 -m 300M abebf7571666 hopeful_morse
Update a new container’s kernel memory constraints
$ $ docker run -dit --name test --kernel-memory 50M ubuntu bash
Update kernel memory while the container is running:
$ docker update --kernel-memory 80M test
Started a container without kernel memory initialized:
docker run -dit --name test2 --memory 300M ubuntu bash
To update restart policy for one or more containers:
$ docker update --restart=on-failure:3 abebf7571666 hopeful_morse
Add a restart policy to a container that was already created
$ docker update --restart=always <container>
Update the "RunningContainerNameOrId" to use 1g of memory and only use cpu core 1
$ docker update --memory "1g" --cpuset-cpu "1" <RunningContainerNameOrID>
To up date all running containers to use core 1 and 1g of memory:
$ docker update --cpuset-cpus "1" --memory "1g" $(docker ps | awk 'NR>1 {print $1}')
Disable auto-restart on a container?
$ docker update --restart=no my-container
Options
Name, shorthand | Default | Description |
--blkio-weight | Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0) | |
--cpu-period | Limit CPU CFS (Completely Fair Scheduler) period | |
--cpu-quota | Limit CPU CFS (Completely Fair Scheduler) quota | |
--cpu-rt-period | API 1.25+ Limit the CPU real-time period in microseconds | |
--cpu-rt-runtime | API 1.25+ Limit the CPU real-time runtime in microseconds | |
--cpu-shares , -c | CPU shares (relative weight) | |
--cpus | API 1.29+ Number of CPUs | |
--cpuset-cpus | CPUs in which to allow execution (0-3, 0,1) | |
--cpuset-mems | MEMs in which to allow execution (0-3, 0,1) | |
--kernel-memory | Kernel memory limit | |
--memory , -m | Memory limit | |
--memory-reservation | Memory soft limit | |
--memory-swap | Swap limit equal to memory plus swap: ‘-1’ to enable unlimited swap | |
--pids-limit | API 1.40+ Tune container pids limit (set -1 for unlimited) | |
--restart | Restart policy to apply when a container exits |
Docker Tutorials Fundamental To Advanced-2021 Crash Course:- https://bit.ly/3hOIbTB













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