How can I change the data directory of Docker where docker save the container (or where lxc save the container)? I have in my server a ssd and a hard drive ant I want that the container will be save on the hard drive. Thanks
6 Answers
I believe that in this guide you'll have a good explanation.
You can change Docker's storage base directory (where container and images go) using the -g option when starting the Docker daemon.
Ubuntu/Debian: edit your
/etc/default/docker
file with the-g
option:DOCKER_OPTS="-dns 8.8.8.8 -dns 8.8.4.4 -g /mnt"
Fedora/Centos: edit
/etc/sysconfig/docker
, and add the-g
option in the other_args variable: ex.other_args="-g /var/lib/testdir"
. If there's more than one option, make sure you enclose them in " ". After a restart, (service docker restart) Docker should use the new directory.Using a symlink is another method to change image storage.
Caution - These steps depend on your current /var/lib/docker being an actual directory (not a symlink to another location).
1) Stop docker:
service docker stop
. Verify no docker process is running ps faux2) Double check docker really isn't running. Take a look at the current docker directory: ls
/var/lib/docker/
2b) Make a backup -
tar -zcC /var/lib docker > /mnt/pd0/var_lib_docker-backup-$(date +%s).tar.gz
3) Move the
/var/lib/docker
directory to your new partition:mv /var/lib/docker /mnt/pd0/docker
4) Make a symlink:
ln -s /mnt/pd0/docker /var/lib/docker
5) Take a peek at the directory structure to make sure it looks like it did before the mv:
ls /var/lib/docker/
(note the trailing slash to6) Start docker back up
service docker start
7) restart your containersresolve the symlink)
-
what is the reason for 4)? Is it needed? In my case, I would like to have docker files to be on a mounted RAID, and not on the boot partition. Feb 27, 2017 at 16:34
In more recent Docker versions on Ubuntu you will edit /etc/default/daemon.json
like so:
{
"data-root": "/new/location"
}
-
$ ls /etc/default/daemon.json ls: cannot access '/etc/default/daemon.json': No such file or directory
Jun 16, 2022 at 6:59
To expand on @MattK's answer:
The Docker documentation on controlling the Docker daemon suggests that platform independent way to do this is:
edit the /etc/docker/daemon.json file (create it if it doesn't already exist) to contain the line
{
"data-root": "/mnt/docker-data",
(...)
}
where /mnt/docker-data
is the directory where you want the docker images and containers to live.
Then
sudo systemctl restart docker
You can check whether it worked by running
docker info
and look for the contents of the line that start with Docker Root Dir:
.
See also https://stackoverflow.com/a/50217666/2209313 and https://unix.stackexchange.com/q/452368/36043.
Note that https://stackoverflow.com/a/68061807/2209313 suggests that if you installed Docker via Snap, you should find your daemon.json
file in /var/snap/docker/current/config/daemon.json
.
-
$ ls /etc/docker/daemon.json ls: cannot access '/etc/docker/daemon.json': No such file or directory
Jun 16, 2022 at 6:58 -
@LuísdeSousa perhaps some of the suggestions in stackoverflow.com/questions/43689271/… would help you find or create your daemon.json file if it is not in the default location specified by the Docker documentation I pointed to Jun 18, 2022 at 17:45
To change the data
directory in docker
it needs to be run with the option -g /my/data
. In my /etc/default/docker
I set:
DOCKER_OPTS="-g /srv/docker"
See also my notes here.
To change the data
directory in lxc
I put in /etc/lxc/lxc.conf
:
lxc.lxcpath = /srv/lxc
-
At the top of that file there is this warning: "THIS FILE DOES NOT APPLY TO SYSTEMD" Jun 16, 2022 at 8:02
Upgrade to Docker 1.13.0.
From the Release Notes:
- New
The storage location of the Linux volume can now be moved
After having upvoted the given answers by Stuart and Conrado, I realized it didn't work, and my system partition went full again.
I actually had to edit the systemd unit file, like described in the following blog article: https://linuxconfig.org/how-to-move-docker-s-default-var-lib-docker-to-another-directory-on-ubuntu-debian-linux.
All together, here are the steps :
sudo systemctl stop docker docker.socket
sudo nano /lib/systemd/system/docker.service
- Change the line
ExecStart=/usr/bin/dockerd -H fd://
intoExecStart=/usr/bin/dockerd -g /new/path/docker -H fd://
and save the file sudo mkdir -p /new/path/docker
sudo rsync -aqxP /var/lib/docker/ /new/path/docker
sudo systemctl daemon-reload
sudo systemctl start docker
Now, my system partition remain slim, the /var/lib/docker
folder is not re-created.
Update following Dan's comment
As Dan stated, updating the Docker packages overrides my update and makes Docker using the default path again.
Following his advice, here is how to properly override the default storage path :
sudo systemctl edit docker
- The above command creates an empty file where you need to copy/past the following :
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -g /new/path/docker -H fd:// --containerd=/run/containerd/containerd.sock
systemctl status docker.service
will ensure all is fine with the override of the Docker configurationsudo systemctl restart docker
Now Docker is using the new place, and you can update the Docker packages without loosing your configuration.
Note : The reason for the empty ExecStart=
is to clear the value from the original file, and the second one fills it again.
-
1The docker documentation says that it should work when updating the
daemon.json
file. Have you restarted docker after changing the config? Otherwise, I wouldn't recommend editing Docker's mainsystemd
file, instead, you should usesudo systemctl edit docker
and override the lines that you want to be overridden. Otherwise, you may lose your changes during an upgrade.– DanMar 25, 2022 at 14:31 -
Yep, I did restart the docker service, but I have updated the
/etc/default/docker
file instead since with Debian like distribution it should be done here, like it is said in the Conrado's answer. Anyway, thank you for sharing thesudo systemctl edit docker
command !– ZedTuXMar 25, 2022 at 14:39