github.com/AliyunContainerService/cli@v0.0.0-20181009023821-814ced4b30d0/docs/reference/commandline/update.md (about) 1 --- 2 title: "update" 3 description: "The update command description and usage" 4 keywords: "resources, update, dynamically" 5 --- 6 7 <!-- This file is maintained within the docker/cli GitHub 8 repository at https://github.com/docker/cli/. Make all 9 pull requests against that repo. If you see this file in 10 another repository, consider it read-only there, as it will 11 periodically be overwritten by the definitive file. Pull 12 requests which include edits to this file in other repositories 13 will be rejected. 14 --> 15 16 ## update 17 18 ```markdown 19 Usage: docker update [OPTIONS] CONTAINER [CONTAINER...] 20 21 Update configuration of one or more containers 22 23 Options: 24 --blkio-weight uint16 Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0) 25 --cpu-period int Limit CPU CFS (Completely Fair Scheduler) period 26 --cpu-quota int Limit CPU CFS (Completely Fair Scheduler) quota 27 --cpu-rt-period int Limit the CPU real-time period in microseconds 28 --cpu-rt-runtime int Limit the CPU real-time runtime in microseconds 29 -c, --cpu-shares int CPU shares (relative weight) 30 --cpus decimal Number of CPUs (default 0.000) 31 --cpuset-cpus string CPUs in which to allow execution (0-3, 0,1) 32 --cpuset-mems string MEMs in which to allow execution (0-3, 0,1) 33 --help Print usage 34 --kernel-memory string Kernel memory limit 35 -m, --memory string Memory limit 36 --memory-reservation string Memory soft limit 37 --memory-swap string Swap limit equal to memory plus swap: '-1' to enable unlimited swap 38 --restart string Restart policy to apply when a container exits 39 ``` 40 41 ## Description 42 43 The `docker update` command dynamically updates container configuration. 44 You can use this command to prevent containers from consuming too many 45 resources from their Docker host. With a single command, you can place 46 limits on a single container or on many. To specify more than one container, 47 provide space-separated list of container names or IDs. 48 49 With the exception of the `--kernel-memory` option, you can specify these 50 options on a running or a stopped container. On kernel version older than 51 4.6, you can only update `--kernel-memory` on a stopped container or on 52 a running container with kernel memory initialized. 53 54 > **Warning**: The `docker update` and `docker container update` commands are 55 > not supported for Windows containers. 56 {: .warning } 57 58 ## Examples 59 60 The following sections illustrate ways to use this command. 61 62 ### Update a container's cpu-shares 63 64 To limit a container's cpu-shares to 512, first identify the container 65 name or ID. You can use `docker ps` to find these values. You can also 66 use the ID returned from the `docker run` command. Then, do the following: 67 68 ```bash 69 $ docker update --cpu-shares 512 abebf7571666 70 ``` 71 72 ### Update a container with cpu-shares and memory 73 74 To update multiple resource configurations for multiple containers: 75 76 ```bash 77 $ docker update --cpu-shares 512 -m 300M abebf7571666 hopeful_morse 78 ``` 79 80 ### Update a container's kernel memory constraints 81 82 You can update a container's kernel memory limit using the `--kernel-memory` 83 option. On kernel version older than 4.6, this option can be updated on a 84 running container only if the container was started with `--kernel-memory`. 85 If the container was started *without* `--kernel-memory` you need to stop 86 the container before updating kernel memory. 87 88 For example, if you started a container with this command: 89 90 ```bash 91 $ docker run -dit --name test --kernel-memory 50M ubuntu bash 92 ``` 93 94 You can update kernel memory while the container is running: 95 96 ```bash 97 $ docker update --kernel-memory 80M test 98 ``` 99 100 If you started a container *without* kernel memory initialized: 101 102 ```bash 103 $ docker run -dit --name test2 --memory 300M ubuntu bash 104 ``` 105 106 Update kernel memory of running container `test2` will fail. You need to stop 107 the container before updating the `--kernel-memory` setting. The next time you 108 start it, the container uses the new value. 109 110 Kernel version newer than (include) 4.6 does not have this limitation, you 111 can use `--kernel-memory` the same way as other options. 112 113 ### Update a container's restart policy 114 115 You can change a container's restart policy on a running container. The new 116 restart policy takes effect instantly after you run `docker update` on a 117 container. 118 119 To update restart policy for one or more containers: 120 121 ```bash 122 $ docker update --restart=on-failure:3 abebf7571666 hopeful_morse 123 ``` 124 125 Note that if the container is started with "--rm" flag, you cannot update the restart 126 policy for it. The `AutoRemove` and `RestartPolicy` are mutually exclusive for the 127 container.