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OpEdge
Industrial Edge Gateway – Release 01.0.00 – 10/2022
6.2 Container Volumes
A container volume allows data to persist, even when a container is deleted. Volumes are also a
convenient way to share data between two or more containers.
Note:
Volume size is dynamic and subject to host storage.
From the container, the volume acts like a folder to store and retrieve data. The volume can be
mounted on the container directory (
/opt/apps/
).
When the user creates a container, two default volumes are created (one default private and one
default public). If a docker image has any volumes included, then the same will be created and
mapped with the container.
By default, the volume location on the host device is:
/var/lib/docker/volumes
.
For volumes deletion, a scheduler will run every 5 minutes to check the consumed volume space
when it exceeds 90% of the reserved space.
Advantages of Volume containers:
•
A docker volume resides outside the container. Since the container resides on the host
machine, the size remains the same after volume creation.
•
User can manage volumes using OpEdge UI.
•
Volumes work on both Linux and Windows containers.
•
Storing data within volumes allows different internal operations (e.g. redeploying a
container with another tag version) to be performed without affecting or losing data.
Common use cases for docker volumes:
•
Providing persistent data volumes for use with containers.
•
Sharing a defined data volume at different locations on different containers on the same
container instance.
•
If a container is recreated due to a failure, a reboot, a new release or any other reason,
the volume data will not be lost.