<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PostalCode"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="State"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="Street"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="address"/>  <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> Hi,<o:p></o:p> <o:p> </o:p> I wonder if any one is familiar with the following, and may help explain what is happening:<o:p></o:p> <o:p> </o:p> I have a Gigabit dedicated connection between two computers: one running Enterprise Linux 3 (EL3), and the other running Fedora Core 5 (FC5). I established an NFS connection in which FC5 exports a directory and EL3 mounts it.<o:p></o:p> <o:p> </o:p> I then start an application in EL3 that gets some “hard real time” data and writes it out to FC5. It is a streaming process, so it would be nice to do this for an extended amount of time.<o:p></o:p> <o:p> </o:p> With this configuration, once the run starts I can see network activity all the time, and activity on the drive in FC5 writing the data. Really looks good. Unfortunately we have occasional events that take a little bit longer than we can afford (hiccups), and the whole thing has to stop.<o:p></o:p> <o:p> </o:p> In trying to find out what the longer event is, I tried to upgrade from EL3 to FC5, i.e. both computers running Fedora Core 5. All the settings being exactly the same, I see a completely different behavior: Now as I start the run, I don’t immediately see any network activity or hard-drive write activity. When I finally see it, it happens at the same time that I get a much longer hiccup.<o:p></o:p> <o:p> </o:p> It appears that it wants to accumulate in a local buffer long enough (about 100 MB) before it starts sending stuff, just that the buffer is way bigger than before for some reason. EL3 is using kernel 2.14.21, FC5 is the “bordeau” dist. I’ve tried to tinker with NFS parameters (async, block sizes, etc) but wasn’t able to reproduce the EL3-FC5 scenario.<o:p></o:p> <o:p> </o:p> Any idea what has changed? <o:p></o:p> <o:p> </o:p> Thanks, <o:p></o:p> <o:p> </o:p> Emanuel<o:p></o:p> <o:p> </o:p> ----<o:p></o:p> Emanuel Machado, PhD.<o:p></o:p> Senior Engineer, Project Leader<o:p></o:p> <o:p> </o:p> <img width=117 height=36 id="_x0000_i1025" src="cid:image001.jpg@01C74F93.CCBF62B0"><o:p></o:p> <o:p> </o:p> Cytonome, Inc.<o:p></o:p> <st1:Street w:st="on"><st1:address tabIndex="0" style="BACKGROUND-POSITION: left bottom; BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x" w:st="on">27 Drydock Ave</st1:address></st1:Street><o:p></o:p> <st1:place w:st="on"><st1:Street w:st="on"><st1:address tabIndex="0" style="BACKGROUND-POSITION: left bottom; BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x" w:st="on"><st1:City w:st="on">Boston</st1:City>, <st1:State w:st="on">MA</st1:State> <st1:PostalCode w:st="on">02210</st1:PostalCode></st1:address></st1:Street></st1:place><o:p></o:p> <st1:Street w:st="on"><st1:address tabIndex="0" style="BACKGROUND-POSITION: left bottom; BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x" w:st="on">Voice: (617) 330-5030 ext. 237</st1:address></st1:Street><o:p></o:p> <st1:Street w:st="on"><st1:address tabIndex="0" style="BACKGROUND-POSITION: left bottom; BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x" w:st="on">Fax: (617) 330-5031</st1:address></st1:Street><o:p></o:p> <st1:address tabIndex="0" style="BACKGROUND-POSITION: left bottom; BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x" w:st="on"></st1:address><st1:Street w:st="on"></st1:Street>Website: <a href="http://www.cytonome.com" title="http://www.cytonome.com">www.cytonome.com</a><o:p></o:p> <o:p> </o:p> Email: <a href="mailto:Emanuel-Machado@cytonome.com">Emanuel-Machado@cytonome.com</a><o:p></o:p> <o:p></o:p> <o:p> </o:p> </div> </body> </html>