CODEWITHSUNDEEP
dockerdocker-container
kane
kane

Reputation: 6017

How to assign more memory to docker container

As the title reads, I'm trying to assign more memory to my container. I'm using an image from docker hub called "aallam/tomcat-mysql" in case that's relevant.

When I start it normally without any special flags, there's a memory limit of 2GB (even though I read that memory is unbounded if not set)

Here are my docker stats

CONTAINER           CPU %               MEM USAGE / LIMIT       MEM %               NET I/O             BLOCK I/O           PIDS
ba57d6c9e9d2        0.22%               145.6 MiB / 1.952 GiB   7.29%               508 B / 508 B       0 B / 6.91 MB       68

I tried setting memory explicitly like so but with same results

docker run -d --memory=10g --memory-swap=-1 -e MYSQL_PASSWORD=password -p 3307:3306 -p 8081:8080 aallam/tomcat-mysql

I've read that perhaps the VM is what's restricting it. But then why does docker stats show that container size limit is 2GB?

Upvotes: 218

Views: 370814

Answers (6)

Michael Warner
Michael Warner

Reputation: 4217

Using Docker update

You can do this with the update command.

update Update configuration of one or more containers

Example

Keep in mind you will need to update the swap normally as well but it should prompt you if you do.

docker update ttdb --memory=1G --memory-swap=1G

Additional Options

You can update more than memory using this command.

  docker container update, docker update

Options:
      --blkio-weight uint16        Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)
      --cpu-period int             Limit CPU CFS (Completely Fair Scheduler) period
      --cpu-quota int              Limit CPU CFS (Completely Fair Scheduler) quota
      --cpu-rt-period int          Limit the CPU real-time period in microseconds
      --cpu-rt-runtime int         Limit the CPU real-time runtime in microseconds
  -c, --cpu-shares int             CPU shares (relative weight)
      --cpus decimal               Number of CPUs
      --cpuset-cpus string         CPUs in which to allow execution (0-3, 0,1)
      --cpuset-mems string         MEMs in which to allow execution (0-3, 0,1)
  -m, --memory bytes               Memory limit
      --memory-reservation bytes   Memory soft limit
      --memory-swap bytes          Swap limit equal to memory plus swap: -1 to enable unlimited swap
      --pids-limit int             Tune container pids limit (set -1 for unlimited)
      --restart string             Restart policy to apply when a container exits

Upvotes: 0

Adrian
Adrian

Reputation: 2388

On Windows with WSL backend, you have to (create and) update the .wslconfig file, located in your users home directory.

Example: %homepath%/.wslconfig

[wsl2]
memory=60GB

(You have to restart WSL and Docker after editing the file)

https://learn.microsoft.com/en-us/windows/wsl/wsl-config#main-wsl-settings

Upvotes: 5

Robert
Robert

Reputation: 36773

That 2GB limit you see is the total memory of the VM (virtual machine) on which docker runs.

If you are using Docker Desktop you can easily increase it from the Whale 🐳 icon in the task bar, then go to Preferences -> Advanced:

Docker Preferences

But if you are using VirtualBox behind, open VirtualBox, Select and configure the docker-machine assigned memory.

See this for Mac:

https://docs.docker.com/desktop/settings/mac/#advanced

MEMORY By default, Docker for Mac is set to use 2 GB runtime memory, allocated from the total available memory on your Mac. You can increase the RAM on the app to get faster performance by setting this number higher (for example to 3) or lower (to 1) if you want Docker for Mac to use less memory.

For Windows:

https://docs.docker.com/desktop/settings/windows/#advanced

Memory - Change the amount of memory the Docker for Windows' Linux VM uses

Upvotes: 325

Derek Soike
Derek Soike

Reputation: 11650

Screen shots for Docker Desktop V3.3.3 (Mac)

Docker Desktop Menu Dropdown

Docker Desktop Preferences

Upvotes: 6

Market Queue
Market Queue

Reputation: 601

Allocate maximum memory to your docker machine from (docker preference -> advance )

Screenshot of advance settings: Screenshot of advance settings.

This will set the maximum limit docker consume while running containers. Now run your image in new container with -m=4g flag for 4 gigs ram or more. e.g.

docker run -m=4g {imageID}

Remember to apply the ram limit increase changes. Restart the docker and double check that ram limit did increased. This can be one of the factor you not see the ram limit increase in docker containers.

Upvotes: 34

Brent
Brent

Reputation: 1488

If you want to change the default container and you are using Virtualbox, you can do it via the commandline / CLI:

docker-machine stop
VBoxManage modifyvm default --cpus 2
VBoxManage modifyvm default --memory 4096
docker-machine start

Upvotes: 24

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