Mike Gerdts wrote: >On Fri, Aug 7, 2009 at 2:11 AM, Henrik Johansen<henrik at scannet.dk> wrote: >> TCP window set to 1024000 : >> A simple cp yields ~82 mb/s >> A simple mv yields ~86 mb/s > >Seems odd that there would be such a big difference. Which cp are you >using? > >With a 5 MB file copying from /tmp to /var/tmp I observe: > >- /usr/bin/cp opens both files, mmap(s) the first one, then does > a single write. >- /usr/gnu/bin/cp skips the mmap and loops through reading and > writing 128 KB chunks.
Small example : henrik at opensolaris:/nfs# rm testfile_5g; ptime /usr/gnu/bin/cp /tmpfs/testfile_5g . real 19.581853675 user 0.318513270 sys 16.105219093 henrik at opensolaris:/nfs# rm testfile_5g; ptime /usr/bin/cp /tmpfs/testfile_5g . real 18.945209146 user 0.015194558 sys 15.547072559 Mount options : henrik at opensolaris:/# nfsstat -m /nfs /nfs from 10.10.10.2:/tmpfs Flags: vers=4,proto=tcp,sec=sys,hard,intr,link,symlink,acl,rsize=1048576,wsize=1048576,retrans=5,timeo=600 Attr cache: acregmin=3,acregmax=60,acdirmin=30,acdirmax=60 Now, without the forcedirectio option and the rsize / wsize modifications I can push the server nic to ~30 % utilization. The client is actually doing more on the server without forcedirectio which puzzles me a bit. >-- >Mike Gerdts >http://mgerdts.blogspot.com/ -- Med venlig hilsen / Best Regards Henrik Johansen
