Hi Quincey, So, I wasn't sure if you saw my other query on this. But, I've got conflicting information regarding the 'multi' (or 'split') vfd.
Is it possible to use the multi (or split) vfd in such a way that RAW data goes to sec2 vfd and all other data streams go to core vfd? I was not sure if your response meant that that is currently not possible or that just having a single vfd act like sort of a core-sec2 hybrid is what is not possible. Mark On Tue, 2010-02-09 at 04:43, Quincey Koziol wrote: > Hi Mark, > > On Feb 8, 2010, at 10:59 PM, Mark Miller wrote: > > > Hi All, > > > > Anyone using the split file driver? > > > > As I understand it, it seems to allow an HDF5 application to 'spread' > > data across one or more files, each one potentially using a different > > vfd. For example, I could have RAW data use the sec2 vfd and all other > > 'meta' data (b-trees, super-block, metadata, etc.) use a core vfd, > > right? > > > > But, can I somehow have RAW datasets BELOW a certain size, say smaller > > than 16 kilobytes, go into the core vfd also but have all other raw data > > go into the sec2 vfd? > > > > Based on what I've read, I don't think this is possible with HDF5 out of > > the box as it appears we can target RAW data to only one vfd in a split > > mode. Am I right? > > > > If so, I wonder if following makes sense... > > > > Create a new sec2 vfd, call it 'sec2_wcore' which will essentially act > > like a mixture of core and sec2 vfds; small writes get handled in core > > like the core vfd does it and large writes get handled as 'normal' like > > sec2 already does handle it. What would the difficulties be in creating > > such a beast? > > Seems like a sensible idea. We have prototyped the idea of "stacking" > VFD's, but it didn't get far enough to put into production. Finishing that > work up so you could have a split VFD on top of the core VFD (for metadata) > and the sec2 VFD (for raw data) would be a really interesting thing. > > Quincey > > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > Hdf-forum@hdfgroup.org > http://*mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org -- Mark C. Miller, Lawrence Livermore National Laboratory ================!!LLNL BUSINESS ONLY!!================ mille...@llnl.gov urgent: mille...@pager.llnl.gov T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-851 _______________________________________________ Hdf-forum is for HDF software users discussion. Hdf-forum@hdfgroup.org http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
