> On 29 Aug 2023, at 8:18 am, Gibney, Dave > <000003b5261cfd78-dmarc-requ...@listserv.ua.edu> wrote: > > Yes, IBM z hardware and z/OS properly sysplexed can achieve many 9s of > reliability. I don't think this is in dispute. > But, computers are tools that perform useful things for people. It should be > clear that actual availability of application function at the outside > endpoints is not nearly as many 9s. > It's fairly clear that even IBM support sites don't run solely on Sysplexed > zHardware under z/OS achieving lot's of 9s.
Nicely articulated. No matter how reliable your servers are if your network provider only offers a 99.99% SLA then your applications are not 99.999% available. IBM zCloud, which runs all the redundancy, only offers a 99.99% SLA which is perfectly reasonable and actually very good https://www.ibm.com/downloads/cas/2DALN6RJ. It’s become fashionable for network service providers to offer 100% availability SLA’s but as usual, the devil is in the detail. If you read the small print it’s quite clear that it’s not worth very much other than marking material for the provider. https://business.bt.com/content/dam/bt/business/v2/PDF/broadband-internet/btnet_sla.pdf > I suspect a few LPARs in Sysplex over a couple CECs running nothing but z/OS > would never need to come fully down. An expensive POC, but also pretty > useless. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
