I might be more concerned that the ESCON channels might be a bottle neck. Some of the factors that will affect the performance on the new DASD would be the speed of the Ficon channels (2 gig, 4 gig or 8 gig) and the internal performance of the new DASD compared to the old DASD.
Paul Feller AIT Mainframe Technical Support 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
