🚀 go-pugleaf

In article <JP107.93Jan22121147@grus.cus.cam.ac.uk>, jp107@cus.cam.ac.uk (Jon Peatfield) writes:
|> Ok, I've had a few nice chats with some of the readers of this group
|> and with our local SGI support line, who are currently off chasing the
|> fact that this has been reported to them before but they couldn't find
|> what had happened last time (what kind of help-desk software does the
|> support line use?)
|> 
|> Anyway it turns out that my SGI Indigos can only push files over NFS
|> at about 10 to 30 Kbytes/sec (after the patch mentioned below) while
|> all the rest of our machines (Sun/HP/Mac), can manage over
|> 110Kbytes/sec (I have a large number of figures if you want them.)  I
|> got a set of patches from SGI for general network performance (a new
|> ethernet device driver), which improved performance a good deal, but
|> still didn't put it in the acceptable range.  After hitting my head
|> for a while and replacing transceivers and moving machines etc, I
|> watched the network with etherfind (great tool -- why don't SGI
|> provide it?) and spotted that the SGIs are waiting after each NFS
|> write for an acknowledgement from the server.  Our servers don't
|> acknowledge 'til the block is on physical disk (like normal machines),
|> so there is a huge wait.  This is as if the biod daemons are not
|> working (but we have four (4) running.)  On all the other machines in
|> the dept, if I have N biods then I don't see blocking 'til N+1
|> requests are outstanding.  The delays get worse when one is over a
|> high latency netwrok while other machines just cope.  What is worse is
|> that if the Acknowledgement reply is lost (as sometimes happens on
|> ethernets (it is UDP after all)), the SGI waits for 4.5 SECONDS before
|> retrying the send.  A few of those and the time really adds up.

it almost sounds like you are hard mounting the nfs mount points...are you
doing that?




-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Miguel (Michael) J. Sanchez
miguel@csd.sgi.com			
Member Technical Staff, Silicon Graphics, Inc.