On Fri, Aug 23, 2013 at 11:46:39AM +0100, Peter Pichler wrote: > > Are you interested in the speed of your storage system, or are you > > interested in how fast your application can move data? > > The former. We have metrics for the latter (well, sort of) but want to > benchmark the storage system, particularly when the storage is on a network > drive.
oh. then just use IOR to a POSIX file and keep HDF5 out of it. HDF5 is going to cache things, or maybe write a byte at the very end before filling in the dataset. ==rob > > What you have done will measure the former, kind of. > > That's what I assumed, but it does not work reliably as I mentioned in my > first post (file growing in large chunks, empty space remaining constant...). > > > What you really want to do is > > - compute how much data application passes to or receives from HDF5 routine > > - time how long routine takes to finish > > I don't really need that kind of metrics. All I need is the overall I/O speed > in MB/s, measured at say 10 seconds intervals (that is, how much raw data we > have shifted to the disk in the past 10 seconds). > > I can try to measure that at the interface that you mentioned. The functions > we use are add_group_string_attribute, add_group_real64_attribute, > add_group_int64_attribute and friends. To measure the I/O speed at this level > I would need to know how calling each of these functions translates to the > number of raw bytes written to the file. It such a translation available? > > Peter > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > [email protected] > http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org -- Rob Latham Mathematics and Computer Science Division Argonne National Lab, IL USA _______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
