Fix the DFS consuming too much memory

The DFS pod is consuming too much memory, its usage increases over time without decreasing. We allocate 10G to this pod, and it is consuming almost all of this memory.

We already exclude a high consumption from the JVM by doing thread dump or using free command inside the container (consumption was about 200Mo at max).

To remember, this pod has a mounted shared volume also mounted in other pods to share the blobs between all microservices.
We currently suspect that this high memory consumption is due to the FS cache of this shared volume, without being able to confirm it.