On 6/8/07, Roch - PAE <Roch.Bourbonnais at sun.com> wrote: > > from the V20z to the V240 gives me a write speed of 80MB/s. So my > > problem is that I get reading speed of 40MB/s over NFS and with the > > same options I get writing speed of 80MB/s. I'm having a really hard > > time to understand this and I was hoping someone here could provide > > some light in this very dark tunnel. > > > > What could cause read speed to be so much slower than write? > > > > This does not look extraordinary to me although, clearly it > could be bettern. > > To write, you're pushing data out, presumably at the speed of > the network with NFS responses (ack) coming in stride. > > To read, it's a request/response load. Send your request > wait for response. Because of the sequential streaming > access pattern, you should be hitting readahead codepath (in > the client client and server filesystem). That might not be > behaving optimally; so at times the network goes quiet while > a server side read is being braught in from disk.
Thanks for your answer. I've continued to bash my head against the server and tried a few more options. 1. I removed the network switched and connected the machines directly with a cable. No changes. 2. I tried multiple reading streams but that doesn't change anything 3. I mounted the server to my linux workstation (running a 2.6.20 kernel) and that machine is capable of reading 80MB/s. So clearly the V240+6140 is able to push the data. This makes me wonder that there must be something wrong/misconfigured with the Solaris 10 nfs client. I've tried googling a lot, checked sunsolve, google.groups but there doesn't seem to be any good answers. Are there any performance related parameters that I can change that could affect the nfs client? cheers, Nickus -- Have a look at my blog for sysadmins! http://aspiringsysadmin.com
