Ryan,
In order to do performance tuning accurately I would need a whole lot more information. Also, I am an AIX guy so I can't help on the mainframe side. So I will just list a few things for you to look at and see if this will help. First of all in order to use Jumbo Frames all devices along the entire path most support Jumbo Frames as well, i.e. switch, routers, sending and receiving systems. The majority of the time my customers have problems with this is when the router or switch either isn't enabled for Jumbos or just doesn't support item. Now if that isn't the problem there are still a few network parameters that could cost you performance. If you increase the tcp send and receive buffers you must also increase the "sb_max" (this is on the AIX side, not sure what you do on the mainframe) to be a value about 1.25X that of the largest send/receive buffer. Another thing to look at is if you increase these socket buffers above 64K then you must enable RFC1323 or else it still only uses 64K buffers regardless of your settings.
also, I might point out that your initial numbers of 22GB in 44 minutes (8.33MB/sec) is pretty slow for a GigE connection. Another issue might be a file I/O problem either reading or writing the data at the sending and receiving ends respectfully.
Let us know how you progress.
-- Regards, Mark D. Rodriguez President MDR Consulting, Inc.
=============================================================================== MDR Consulting The very best in Technical Training and Consulting. IBM Advanced Business Partner SAIR Linux and GNU Authorized Center for Education IBM Certified Advanced Technical Expert, CATE AIX Support and Performance Tuning, RS6000 SP, TSM/ADSM and Linux Red Hat Certified Engineer, RHCE ===============================================================================
Miller, Ryan wrote:
Here's a question from one of my cohorts, since this is our first try at this, I thought I would see if I could get any input from anyone else doing this.
We have been testing jumbo frames(8990) using TSM on an AIX client. The base line test with MTU of 1500 moved 22G in 44 minutes. Changing the MTU to 8990 and the TCP receive and send buffer sizes on both the mainframe and AIX client to 256K, the same 22G of data takes 1 hour and 40 minutes.
Also the largest input packet size is 8192, not 8940. Are their any tcp parameters to se on the client that would help with the jumbo frame transfer time?
Ryan Miller
-----Message Disclaimer-----
This e-mail message is intended only for the use of the individual or entity to which it is addressed, and may contain information that is privileged, confidential and exempt from disclosure under applicable law. If you are not the intended recipient, any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by reply email to [EMAIL PROTECTED] and delete or destroy all copies of the original message and attachments thereto. Email sent to or from the Principal Financial Group or any of its member companies may be retained as required by law or regulation.
Nothing in this message is intended to constitute an Electronic signature for purposes of the Uniform Electronic Transactions Act (UETA) or the Electronic Signatures in Global and National Commerce Act ("E-Sign") unless a specific statement to the contrary is included in this message.
