[OpenAFS] Re: OpenAFS 1.7.x on windows and IBM Tivoli Fastback Continuus Data Protection

David Boyes dboyes@sinenomine.net
Thu, 15 Dec 2011 09:56:58 -0600

> > > Just one question: does someone use IBM Tivoli Continous Data
> > > Protection Software and save that backup onto OpenAFS 1.7.x
> > > \\AFS\... ?
> >
> > TCDP makes extensive use of symlinks and byte-range file locking. I
> > doubt it would work well in AFS.
> Well, byte-range locks between machines or on the same one? We should
> be able to handle them between processes on the same client pretty well o=
> some platforms.

"It depends".  The Unix and Windows implementations of TDCP take very diffe=
rent approaches to updating the data stores, and the z/OS implementation is=
 different yet in that it's handled almost exclusively in the CF locking su=
bsystem for global dataset locks and the app doesn't have to deal with it. =
 Weird, but screamingly efficient on that platform. There are also about 14=
 zillion ways to set up datastores.

Usually TDCP is updating a remote data store (otherwise not much point in r=
unning it), so it would involve multiple machines. If you wanted a general =
model, it's more like running a DBMS than writing to a file. That kind of w=
orkload (from what I've observed) doesn't seem to work very well in AFS wit=
hout some contortions, and your backup data is the last place you want to e=
xperiment with "weird".=20