github.com/flavio/docker@v0.1.3-0.20170117145210-f63d1a6eec47/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  
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    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 value          Block IO (relative weight), between 10 and 1000
    25        --cpu-period int              Limit CPU CFS (Completely Fair Scheduler) period
    26        --cpu-quota int               Limit CPU CFS (Completely Fair Scheduler) quota
    27    -c, --cpu-shares int              CPU shares (relative weight)
    28        --cpu-rt-period int           Limit the CPU real-time period in microseconds
    29        --cpu-rt-runtime int          Limit the CPU real-time runtime in microseconds
    30        --cpuset-cpus string          CPUs in which to allow execution (0-3, 0,1)
    31        --cpuset-mems string          MEMs in which to allow execution (0-3, 0,1)
    32        --help                        Print usage
    33        --kernel-memory string        Kernel memory limit
    34    -m, --memory string               Memory limit
    35        --memory-reservation string   Memory soft limit
    36        --memory-swap string          Swap limit equal to memory plus swap: '-1' to enable unlimited swap
    37        --restart string              Restart policy to apply when a container exits
    38  ```
    39  
    40  The `docker update` command dynamically updates container configuration.
    41  You can use this command to prevent containers from consuming too many
    42  resources from their Docker host.  With a single command, you can place
    43  limits on a single container or on many. To specify more than one container,
    44  provide space-separated list of container names or IDs.
    45  
    46  With the exception of the `--kernel-memory` option, you can specify these
    47  options on a running or a stopped container. On kernel version older than
    48  4.6, you can only update `--kernel-memory` on a stopped container or on
    49  a running container with kernel memory initialized.
    50  
    51  ## Examples
    52  
    53  The following sections illustrate ways to use this command.
    54  
    55  ### Update a container's cpu-shares
    56  
    57  To limit a container's cpu-shares to 512, first identify the container
    58  name or ID. You can use `docker ps` to find these values. You can also
    59  use the ID returned from the `docker run` command.  Then, do the following:
    60  
    61  ```bash
    62  $ docker update --cpu-shares 512 abebf7571666
    63  ```
    64  
    65  ### Update a container with cpu-shares and memory
    66  
    67  To update multiple resource configurations for multiple containers:
    68  
    69  ```bash
    70  $ docker update --cpu-shares 512 -m 300M abebf7571666 hopeful_morse
    71  ```
    72  
    73  ### Update a container's kernel memory constraints
    74  
    75  You can update a container's kernel memory limit using the `--kernel-memory`
    76  option. On kernel version older than 4.6, this option can be updated on a
    77  running container only if the container was started with `--kernel-memory`.
    78  If the container was started *without* `--kernel-memory` you need to stop
    79  the container before updating kernel memory.
    80  
    81  For example, if you started a container with this command:
    82  
    83  ```bash
    84  $ docker run -dit --name test --kernel-memory 50M ubuntu bash
    85  ```
    86  
    87  You can update kernel memory while the container is running:
    88  
    89  ```bash
    90  $ docker update --kernel-memory 80M test
    91  ```
    92  
    93  If you started a container *without* kernel memory initialized:
    94  
    95  ```bash
    96  $ docker run -dit --name test2 --memory 300M ubuntu bash
    97  ```
    98  
    99  Update kernel memory of running container `test2` will fail. You need to stop
   100  the container before updating the `--kernel-memory` setting. The next time you
   101  start it, the container uses the new value.
   102  
   103  Kernel version newer than (include) 4.6 does not have this limitation, you
   104  can use `--kernel-memory` the same way as other options.
   105  
   106  ### Update a container's restart policy
   107  
   108  You can change a container's restart policy on a running container. The new
   109  restart policy takes effect instantly after you run `docker update` on a
   110  container.
   111  
   112  To update restart policy for one or more containers:
   113  
   114  ```bash
   115  $ docker update --restart=on-failure:3 abebf7571666 hopeful_morse
   116  ```
   117  
   118  Note that if the container is started with "--rm" flag, you cannot update the restart
   119  policy for it. The `AutoRemove` and `RestartPolicy` are mutually exclusive for the
   120  container.