On Thu, 17 Apr 2008, Burke, S (Stephen) wrote:
Can we collapse the tape with the cache into a single Datastore that has both an Online and a Nearline component?
I would say not, the basic idea of a Datastore is to make it homogeneous. Is there a real problem with having a many-to-many relation between Share and Datastore? In LDAP I think it's OK, you just put
No, I do not have a problem with that. My point is that the very same facility that provides the tape may at the same time control the disk: the disk would just be the online component of the tape store, and not something that one has to foresee separately, if desired. In principle a tape store does not _have_ to have disk (e.g. central data recording in CASTOR-1 could write directly to tape), but if it has disk, that disk is directly managed by the same software that manages the tape, so I felt we might want to express that explicitly by putting an online component alongside the nearline component of the DataStore.