Can metadata I/O mode for parallel write be independent?


#1

Hi, all,

I have a question about metadata write mode.
The HDF5 document linked below says “When engaging in parallel I/O, all metadata write operations must be collective.”.

https://support.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetAllCollMetadataOps

However, I called H5Pset_coll_metadata_write() with ‘false’, it works well with Independent I/O.
Also, the HDF5 document linked below says “If independent access is selected, the library uses the default method for doing metadata I/O either from process zero or independently from each process.”
It looks like metadata write can work using independent I/O.

https://support.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetCollMetadataWrite

Which one is the correct description? Can I use independent I/O mode for metadata in parallel applications?