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App Data Directory

Apps store their data and assets in the /home/yellowtent/appsdata/<appid> directory. If the server is running out of disk space (in the root filesystem), you can move the app's storage directory to another location. In most cases, this is an external disk mounted on the server. For example, you can mount a DigitalOcean Block Storage or AWS Block Store and move the app's data to that disk.

For example, to move an app's data to an external disk location like /mnt/nextcloud, go to the Storage section:

App Data Directory is backed up

The external app data directory is part of the app's backup.


On Cloudron, each app is run in a separate container and the users inside the container are different from the host system (and the uid is the container can change across updates).

Unfortunately, CIFS does not have a concept of users and groups. For this reason, CIFS is not a supported file system for external app directory.


Mount the NFS share into your server by putting the following in /etc/fstab:

IP:/remote_volume /appdata/myapp nfs rw,hard,tcp,rsize=8192,wsize=8192,timeo=14 0 0 


Apps on Cloudron are containerized and do not have access to the server's file system. To provide an app access to a path on the server, one can create a Volume and then mount the volume into the app.

  • Volumes can be mounted into one or more apps.
  • These can be NFS/SSHFS mounts or external storage disks attached to the server. Any file system that be mounted on the server will work.
  • When mounting into an app, you can specify if it should be read-only or not.
  • For security, only paths under /mnt, /media, /srv, /opt can be added as a volume's host path.

Once added, these volumes can be mounted on to one or more apps.

Volumes are not backed up

Volumes are not backed up. Restoring an app will not restore the volume's content. Please make sure to have a suitable backup plan for each volume.


Apps on Cloudron are run in containers (usually as non-root user). Generally, this user is www-data (uid 33) or the cloudron (uid 100) user. If you want to make the app write to a volume, you must ensure that the host directory has permissions to allow writes from these usernames. For maximum compatibility, you can just allow all users to write to the host path - chmod a+w /mnt/songs. This approach should allow pretty much any app to write to the directory. You can always use the read-only flag when mounting to ensure that specific apps cannot write.

Disk layout

Most of the Cloudron code and data is sandboxed in /home/yellowtent (For the curious, yellowtent was the code name for Cloudron). The subdirectories are:

  • box - This contains the Cloudron code. The Cloudron code does not run as root.
  • boxdata - This contains data that is generated by the Cloudron code including certs. This also contains all user emails in the mail/vmail directory in the maildir format.
  • appsdata - This contains the data generated by each app. Each directory here corresponds to the application id.
  • platformdata - This contains 'runtime' data of the platform for mysql, postgres, mongodb, nginx.

boxdata, appsdata and platformdata are relocatable.

The other important locations on the server are:

  • /var/lib/docker - This contains docker images. This is relocatable.
  • /etc/nginx - These contains the reverse proxy configuration. It is not meant to be edited manually.
  • /apps.swap - This is a swap file that is dynamically resized by Cloudron. It will be no more than 4GB. You can resize this to any size after the initial setup. If you want to disable the swap altogether, just truncate the file to 0 size.

Docker images

Cloudron uses Docker for containerizing applications and docker images tend to consume a lot of space. The docker images are stored by default at /var/lib/docker. They can be moved to an external storage as follows:

  • Stop docker and the box code:
systemctl stop docker box
  • Change docker image location to say /mnt/docker by creating a systemd drop-in /etc/systemd/system/docker.service.d/custom.conf with the following contents:
ExecStart=/usr/bin/dockerd -H fd:// --log-driver=journald --exec-opt native.cgroupdriver=cgroupfs --storage-driver=overlay2 --graph=/mnt/docker
  • Start docker
systemctl daemon-reload
systemctl start docker
systemctl status docker
docker network create --subnet= --ip-range= cloudron
  • Now edit the file /home/yellowtent/platformdata/INFRA_VERSION. Bump the version field carefully by only adjusting the last digit from 48.18.0 to 48.18.1. Do not change the other digits. This is just a way to inform the cloudron code that the infrastructure has changed and it has to re-create containers.

  • Reboot the server. This is required for the docker network to start working in many VPSes (for unknown reasons).

  • On reboot, addons and app images will be recreated preserving existing data. This can take a while. You can use tail -f /home/yellowtent/platformdata/logs/box.log to see the progress.

  • Finally, after everything is up, you can remove the old docker images

rm -rf /var/lib/docker

Docker image size

The du -hcs /var/lib/docker command will often return incorrect output with the overlay2 driver because of how du works. Use docker system df instead to determine the size

Docker storage driver

Cloudron apps are only tested using the overlay2 graph driver. Other storage drivers are not tested. In the past, we have seen some apps to not work correctly with storage drivers like devicemapper.

Default Data Directory

Please make sure you have a complete backup before following the procedure below.

Apps store their data under /home/yellowtent/appsdata. Cloudron itself stores it's data (users, groups, certs, mails etc) under /home/yellowtent/boxdata.

If the server is running out of disk space, one or more of these directories can be moved to another ext4 disk/location as follows:

    systemctl stop box
    systemctl stop docker
    DATA_DIR="/var/data"  # this is the external disk location
    mkdir -p "${DATA_DIR}"

    # (optional) move out apps data to the external disk
    mv /home/yellowtent/appsdata "${DATA_DIR}"
    ln -s "${DATA_DIR}/appsdata" /home/yellowtent/appsdata

    # (optional) move out box data to the external disk
    mv /home/yellowtent/boxdata "${DATA_DIR}"
    ln -s "${DATA_DIR}/boxdata" /home/yellowtent/boxdata

    # (optional) move out app database storage to the external disk
    mv /home/yellowtent/platformdata "${DATA_DIR}"
    ln -s "${DATA_DIR}/platformdata" /home/yellowtent/platformdata

    systemctl start docker
    systemctl start box

If the disk graph does not display properly, do a systemctl restart collectd.

Note: data directory must be an ext4 filesystem.

Server Resize

For VPS providers that support it, the server (cpu/disk/memory) can be resized and Cloudron will automatically adapt to the available resources after a server restart.

IP changes

Some VPS providers change the IP address of the virtual machine after a resize. You will have to change the IP address in your DNS, if this is the case.


On AWS, the partition and the filesystem must be resized after resizing the EBS volume. This can be done by following the AWS Guide.


To give the server more swap space, run the following commands:

dd if=/dev/zero of=/extra.swap bs=1024 count=2097152
chmod 600 /extra.swap
mkswap /extra.swap
swapon /extra.swap

To make sure the swap persists reboots, add a line in /etc/fstab:

/extra.swap  none  swap  sw  0 0