[Hdf-forum] writing data as fast as possible

[Ger van Diepen]

We have an instrument generating several GBytes/second. 
We would like to dump these data as fast as possible to disk (of course
in a parallel way), preferably with O_DIRECT to bypass the OS file cache
and to avoid seeks to maintain meta data. 
Yet, it would be nice if these data can be seen as an HDF5 dataset. 

My question is if it possible to do something like this. Either that
HDF5 has the option to write data in this way or through some mechanism
that HDF5 can treat such an external file as HDF5 data, possibly by
dynamically loading a shared library that knows how to interpret the
data. 

I'm asking this because we have the impression that something like an
extendible dataset does not give us the performance/robustness we need.
In case of a crash we would like to lose as few data as possible, which
means that a regular flush has to be done which might kill performance.
I guess that without a flush the indices are only written at the end, so
the data cannot be found in case of a crash. 

Cheers, 
Ger van Diepen 

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