Radoslaw, Actually RMF does not report channel utilization for FICON. It is showing you microprocessor busy on the host channel board.
For the same MB/sec this metric will change depending on block size, data length and whether zHPF is used. You can quite easily saturate a host channel MP with small blocksizes. I haven't measured the 8S channels yet - we're just installing them - but I think that with non-zHPF and 4KiB single blocks they would run out of steam at around 200MB/sec (50K IOPS). I think Cathy Cronin has published a paper with better numbers than my wild asses guess. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Mike Schwab > Sent: Tuesday, March 06, 2012 1:23 PM > To: [email protected] > Subject: Re: [IBM-MAIN] FICON channel ulitization > > No. You are dealing with one device and no intermediate device to buffer > the transmission rates. Transmission rate is negotiated to the fastest rate > that both ends support. > > Both ends are transmitting at that same rate, and are busy for the same > amount of time. > > In contrast, say you were downloading over the internet through several > devices. The source could send the file at full speed, but is buffered by a > device in the middle. It is relaying the data at a slower rate over a slower link > to you. > > On Tue, Mar 6, 2012 at 3:12 PM, R.S. <[email protected]> > wrote: > > W dniu 2012-03-06 21:33, Mike Schwab pisze: > If the receiving switch > > is 4G, that is the maximum transmission rate > from the 8G channel. > > > It was busy 100% at 4G. I think I understand it now. So, chpid > > connected to 8G sfp on the switch, then to 4G CU would show 50% > > utilization? Radoslaw Skorupka Lodz, Poland > -- > Mike A Schwab, Springfield IL USA > Where do Forest Rangers go to get away from it all? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
