Hi everyone, I'm not sure, whether the lustre or the MPI forum is the right place for my question. The question is about the ROMIO optimization on Lustre, In one SC'08 paper, http://users.eecs.northwestern.edu/~wkliao/PAPERS/fd_sc08_revised.pdf<https://mail.ttu.edu/owa/redir.aspx?C=yUmbVUH4hUWLFEWFA2GcoiKOEhnhitAIatZfGT92-aN2MTXitjDjPgfE9EfJkJF9q3XAaOQ_iME.&URL=http%3a%2f%2fusers.eecs.northwestern.edu%2f%7ewkliao%2fPAPERS%2ffd_sc08_revised.pdf> , it's said that the way ROMIO assigns the file domains to I/O aggregators will not make two aggregators access the same OST. In my understanding, this means, the data locality on Lustre layer has been taken care of in the ROMIO, such that the aggregators will not have competition on the same OST. My question is "is this optimization used in all current lustre system, e.g., Hopper at NERSC?" Thanks, Jailin Liu Ph. D student Texas Tech University