Better display and accounting for local volumes

[neunhoef]

Currently, if one asks for a non-default size in a persistent volume which is provided by our storage operator, no accounting and limiting is done whatsoever. Furthermore, the volume is always shown with the default size of 8Gi, which is confusing.

We should at least show it with the size that was requested.

Furthermore, we should probably know how much disk space the administrator has reserved for a particular ArangoStorage resource and do accounting such that we do not oversubscribe.

Finally, in the end we should enforce specified limits with some clever bind mounts.

[orifito]

Any update on this? I don't see volumes shown with the default size of 8Gi. What is confusing is that pods always get the maximum size of local SSD disks, regardless of the size requested.