Clarification of Image.Config.Volumes

[runcom]

the spec reads:

A set of directories which SHOULD be created as data volumes in a container running this image.

How should runtimes handle/translate volumes? is there any correct way? what's the definition of a data volume? Is it a directory on the host (bind)mounted in the container?

/cc @cyphar @vbatts

[runcom]

probably related to #492

[cyphar]

Feels like a dup of #496, where I was trying to get some sort of explanation of how volumes should act with regards to layers.

[cyphar]

And #504 is the PR with some wording but I haven't touched that in a while.

[jonboulle]

IMO this is covered by https://github.com/opencontainers/image-spec/pull/492/files#diff-8aafbe2c3690162540381b8cdb157112R91 ; @runcom if you disagree feel free to reopen.