Richard, A couple question: How is your FICON Switch fabric configured, is this a single switch or cascaded switches between the channels and your DASD CU's? What is the link speed of your FICON Channels, 2Gb, 4Gb or 8Gb? If the LPAR's are running on a z10 you might benefit from the zHPF (high performance FICON feature on the z10), which reduces the number of bi-directional exchanges for each I/O.
Also, depending on the FICON Switches in your shop, you should be able to monitor the FICON channel port utilization real time by using the web-based or CLI based switch port performance displays (eg. Brocade portperfshow cmd). I can give you a few tips if you wish to contact me offline. Regards Mike Rydberg Brocade ________________________________ From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On Behalf Of Schuh, Richard Sent: Wednesday, February 17, 2010 1:14 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Channel Contention Currently, we have 3 LPARS, 2 support Linux and 1 for TPF testing. The current disk configuration is * a boatload of big 3390s (27-32MB) are on the Linux LPARs, These are connected using 4 Ficon channels. The DDRs will be done from one of the Linux LPARs. There will be two concurrent DDRs for this. These will be full disk copies. 4 channels to 210 disks. * Another boatload of 3330-03s where the TPF test system base disks reside. These are connected to the third LPAR via 8 ESCON channels to each array. Since the disks are not the same size, the minidisks will be copied, not the physical disks. The plan is to have 16 concurrent copies. There are 16 channels serving 437 disks, roughly 15,000 minidisks. * The target disks are connected via 4 Ficon channels that are EMIFd to all LPARs. There is separation of arrays; the TPF and Linux disks are not intermingled; however, the same 4 channels are shared between the LPARs. There are only 4 channels. The question is, will the 4 channels be a bottleneck if both the Linux and TPF migrations are done concurrently? Regards, Richard Schuh
