But no matter how many ESCON channels you put on a 3590-A50, you cannot run it at full speed. Eight ESCON channels cannot pump as much data through an A50 as one 2Gb FICON can, IMO. The speed increase I go going from ESCON to FICON on A50s was far more than I expected, particularly with smaller block sizes.
>>> "Pommier, Rex R." <rex.pomm...@cnasurety.com> 2/24/2010 10:09 AM >>> Fred, While I cannot directly answer your question (specifically the concurrent part), my guess is that the issue behind the question is that you're not driving your 3590s at full speed due to ESCON channel limitations. We have a 3590-A50 with 4 3590-B11 transports behind it. It had a single 17 MB ESCON channel in front of it and our backups were running slow, with the ESCON channel maxed out during the entire backup. We added a second ESCON adapter to the A50 and our backup speed jumped dramatically, with both ESCON channels being pushed at times to full utilization. So even if they're not concurrent, the A50 can absorb more I/O than 2 ESCON channels can provide to it. HTH Rex -----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Fred Schmidt Sent: Tuesday, February 23, 2010 6:19 PM To: IBM-MAIN@bama.ua.edu Subject: 3590-A50 ATL maximum concurrent I/O's per CU How many I/O's can a 3590-A50 control unit do *concurrently*? The "3590 Intro. and Planning Guide" in section 1.2.2 says ... ------------------------------------------------------------------------ ---------------------------------------------- Model A50 provides a single data transfer path with one (FC3311) or two (FC3311 and FC3312) ESA/390 ESCON channel attachment adapters. ------------------------------------------------------------------------ ---------------------------------------------- But does this mean 1x I/O per CU total? Or 1x I/O per path to the CU, which would be 2x I/O's total for us? Regards, Fred Schmidt Data Centre Services, NT Government Australia ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html CONFIDENTIALITY/EMAIL NOTICE: The material in this transmission contains confidential and privileged information intended only for the addressee. If you are not the intended recipient, please be advised that you have received this material in error and that any forwarding, copying, printing, distribution, use or disclosure of the material is strictly prohibited. If you have received this material in error, please (i) do not read it, (ii) reply to the sender that you received the message in error, and (iii) erase or destroy the material. Emails are not secure and can be intercepted, amended, lost or destroyed, or contain viruses. You are deemed to have accepted these risks if you communicate with us by email. Thank you. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
