Hi, 22.09.2009 21:32, Blake Dunlap wrote: >> Hmm... that's not what I intended originally (though, as I'm not >> working on it myself, I won't object if somebody else does it >> differently). >> >> A volume that is actually written is by definition in a Location >> with cost=0; the default would be LocationId=0. Everything else >> does, IMO, not make sense. >> >> If you unload that volume, you'd mark it to be in a different >> location. >> >> Arno > > My reasoning for the above is SDs in multiple datacenters. I > definitely see the usefulness for locations to not be assumed to be > local until removed. You can use this along with pools to set up > offsite pools for other locations etc and have a nice automated > tier system of capabilities spanning multiple sites.
Ok, now I see what you're aiming at - my original concept doesn't allow that easily, though. We'd need a concept of locations for SDs, too, which wouldn't be too hard (i.e., in the SD conf, per device, we might have an optional "Location = whatever" setting. A volume used by that device would then be assigned the defined location. Only the cost concept needs refinement - a volume in data center A is available at low cost there, while cost for transport to data center B would be high... from a database PoV this is simple, though it needs a catalog change (which is one of the starting points of this discussion...) Imagine table Location: LocationId Name CostId <= Changed Enabled Add table Cost: CostId <= NOT unique! ForLocation Cost Now you could have those Locations: 1 "DC A" 1 2 "DC B" 2 3 "storage" 3 and Cost 1 1 0 1 2 50 1 3 30 2 1 50 2 2 0 2 3 30 3 1 30 3 2 30 3 3 0 What I tried to model - and it's likely this can be done better - is that a volume in Location 3 (called storage) can be moved at cost 30 to DC A and DC B. A volume in DC A can be moved at cost 50 to DC B, and so on. A bit more complex than the existing concept, but it allows to model several paths of volumes through an organization. It would also allow to disable paths by assigning infinite (or -1) costs... say we never want volumes to go from DC A to DC B directly, and vice versa: 1 2 -1 2 1 -1 Hmm... I'll need to paint a picture :-) I get interested in this stuff again... Arno -- Arno Lehmann IT-Service Lehmann Sandstr. 6, 49080 Osnabrück www.its-lehmann.de ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ Bacula-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
