operation messages fig4 shows an example of a pnfs client 103 or 104 which is equipped with fc hba 405 and is connected to fc san 114 it has memory 401 cpu 402 i o 403 nic 404 connected to the ip lan 113 fc hba 405 connected to the fc san 114 and internal storage 406 the memory 401 also executes user programs 407 os 408 and as os internal components a file system program 409 a pnfs client program 410 a nfs client program 411 a tcp ip program 412 and a fc program 413 these components work according to the protocol specified in the rfc 5661 and rfc 5663 the pnfs client program 410 sends a nfs message to the layout management server 105 to retrieve block layouts it then sends fc commands to the block storages 111 and 112 to read and collect file data fig5 shows an example of the pnfs client 101 which is equipped with nic 504 that is connected to the ip lan 113 and does not have fc hba it includes memory 501 cpu 502 i o 503 nic 504 and internal storage 505 these components are connected with each other via an internal bus on the memory 501 the pnfs client 101 executes multiple user programs 506 and also an os 507 including file system program 508 pnfs client program 509 nfs client program 510 and tcp ip program 511 these components work according to the protocol specified in the rfc 5661 the pnfs client program 509 sends a nfs message to the layout management server 105 to retrieve file layouts it then access nfs data servers 109 and 110 fig6 shows.