Just to explain why we need two LPARs. The application uses a VSAM dataset which is updated for all incoming transactions. If we want to run two instances of that application on two different LPARs to provide availability even if one of the LPARs goes offline for any reason, then the VSAM dataset needs to be shared across the two instances when both are running to support concurrent access.
The only other option for the two LPARs on the same CEC is possibly VSAM ShareOptions but given this is a package from a vendor, it might not be coded to support the right queueing and de-queueing of access to that dataset. > .. > > 2. Just in case there's any confusion.... VSAM RLS (and Transactional > VSAM, i.e. z/OS DFSMStvs) do(es) not require two or more z/OS instances. A > single z/OS instance with a single CF is the minimum configuration for > those VSAM features. > > 3. If you do run two or more z/OS instances (a "Parallel Sysplex in a > box") that can be a lovely configuration, but just bear in mind if the site > or machine go offline (planned or unplanned) then you lose the whole > Sysplex. Nonetheless a "Parallel Sysplex in a box" provides a great deal of > value in terms of protecting against various software-related issues that > would affect service availability if you only had one z/OS instance. > Hypothetically a single CF could topple over and/or require a planned > outage even without anything else going offline, but even with one CF the > "Parallel Sysplex in a box" is rather good. > > 4. Check for and apply all relevant firmware, z/OS, and middleware updates > (of course). > > — — — — — > Timothy Sipples > Senior Architect > Digital Assets, Industry Solutions, and Cybersecurity > IBM zSystems/LinuxONE, Asia-Pacific > [email protected] > > > ---------------------------------------------------------------------- > 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
