Perhaps my knowledge of virtual memory has been supplanted by too much other junk.
Recently I ran some database benchmark tests where all data was to be stored on an NFS server and accessed via NFSv3 mounts. While importing data into the database (over the network via a separate host) I ran
sar to collect various statistics at 1 second intervals. When complete (after GiBs of data being read from and written to the NFS server), I expected the
pgpgout/s entries to be quite high. Instead they were mostly zero with a few moderately large entries. Average faults/s on the other hand were in the hundreds of thousands. The database server is equipped with 256 GiB RAM. Does the minimal paging indicate that nearly everything read from or written to the NFS server initially fit in cache and stayed there for the remainder of the import? What am I not understanding?