Hi Stephen, Burke, S (Stephen) wrote:
Sergio Andreozzi [mailto:sergio.andreozzi@cnaf.infn.it] said:
in the current modeling, it cannot be implied because storageResource is associated to a dataStore via a many-to-many relationship.
It would have been possible in this case: storageResource 1--* dataStore
That seems to be a mistake, Datastore to Resource should indeed be many to 1. I don't think it could make sense for one piece of hardware to be managed by multiple systems.
I'm not sure about this. Within a storage area networks you can find several servers sharing storage devices such as disk subsystem and tape libraries and also data stored upon them. SAN aggregate and share the storage devices via volume manager. You can deploy some different file systems upon the same SAN infrastructure. I imagine a cluster file system, like GPFS, managing the disk system and TSM managing the mass storage system. Both systems are using the same SAN. Moreover, the storage administrator could build several file systems using GPFS, for example one per supported VO. Now, if I've understood well, there are only two/three DataStores: - one to represents the "disk quality", - one to represents the "tape quality", - and, eventually, one to represents the "hierarchical-system" not manageable by user. But, at the same time, we have a set of StorageResources corresponding to File Systems created.. Is it correct above description? If yes, I cannot be able to assign Size properties to DataStores.. vice versa I can assign sizes to StorageResources. If no, I don't understand what DataStore is. We could move Size properties to StorageResources and make a relationship between StorageShare <-> StorageResource and between StorageResource <-> DataStore (many-to-many). In this way we can represents above example, I think. I don't know about the relationship between StorageShare and DataStore. Perhaps it is still needed.
Stephen
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