One or the other, not both. It's OK to use either/or on a catalog by catalog basis, but you cannot double down. Reference z/OS 2.2.0 DFSMS Managing Catalogs - Accessing Catalogs for Record Level Sharing, Restrictions:
* Master catalogs are currently not supported in RLS mode. Ensure that any catalog in RLS mode is not being shared as a master catalog by any system in the plex. * RLS protocol cannot be used simultaneously with either ECS or VVDS protocol for a catalog. This is enforced by the SMSVSAM address space. If you attempt to use a catalog currently in RLS mode from a non-RLS system in the sysplex, the associated catalog request will fail with return code RC4 and reason code RSN124. If a catalog is currently in either ECS mode or VVDS mode and is shared by a system that cannot support RLS for catalogs, the attempt to use the catalog in RLS mode will also fail with return code RC4 and reason code RSN124. To place a catalog in RLS, it must be SMS-managed, and the SMSVSAM server must be active on all systems in the sysplex. You can move a catalog in and out or RLS mode with RLSQUIESCE and RLSENABLE, for emergency or maintenance purposes, but it's not recommended to do so frequently. We put all of our user catalogs in RLS, except for two specific catalogs with system-critical dataset entries, that don't get hit that often. These are in VLF. RLS seems to be the better performing option for us. Art Gutowski General Motors, LLC On Thu, 23 Apr 2020 16:43:44 +0000, Allan Staller <allan.stal...@hcl.com> wrote: >ITYM ECS. (Enahnced Catalog Sharing). > >ECS is specific to catalogs and uses a structure for inter-image communication. >RLS uses a local address space (SMSVSAM) for local communication AND a >structure for inter-image communication. > >Both are performance related. > >IMO, RLS is more appropriate for applications. ECS is less overhead. > >ECS should be sufficient for most purposes. I have not researched the >practicality or mpact of attempting both on the same catalog (KSDS). > >-----Origanal Message----- >From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of >Peter Vander Woude >Sent: Thursday, April 23, 2020 9:29 AM >To: IBM-MAIN@LISTSERV.UA.EDU >Subject: Catalogs in parallel sysplex ECS vs RLS > >Ok, building parallel sysplex. Forhthe catalogs I am planning on using ECS >for the shared catalogs (which is all of them). > >What is the recommended method for handling the catalogs in a parallel >sysplex, ECS or VSAM RLS? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
