Hi everybody, I have a question about the PVFS2 write performance.
We did some measurements with BTIO over PVFS2 on lonestar at TACC (http://www.tacc.utexas.edu/services/userguides/lonestar/) and we get pretty bad write results with classes B and C: http://www.arcos.inf.uc3m.es/~florin/btio.htm We used 16 I/O servers, the default configuration parameters and upto 100 processes. We realized that all I/O servers were used also as metadata servers, but BTIO uses just one file. The times are in seconds, contain only I/O time (no compute time) and are aggregated per each BTIO run (BTIO performs several writes). TroveSyncMeta was set to yes (by default). Could this cause the I/O to be serialized? It looks as if there were a serialization. Or could the fact that all nodes were also launched as metadata managers affect the performance? Any clue why this happens? Many thanks Florin _______________________________________________ Pvfs2-users mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
