I have done a lot of these types of conversions, strangely enough, the biggest jump I have ever performed (so far) was just this year at a small local government site that was still running MVS/ESA who moved to zOS 2.2, they were running on a 4381 and migrated to a z13s. The total outage was about 4 hours only because I had to copy (ALL of) the DISK volumes to tape and then back to disk on the go-live day, but it could have been much less had they allowed me to stage things a little differently. The hardest part was making the volume copies under MVS/ESA that could still be read on z/OS. I ended up writing a program to to the full pack backups and restores. DASD to DASD would have been much better, but they had REAL 3350's and 3380's and only FICON RAID on the new system. That was a real test of the process.:)
Any way, your client can run OS/390 2.5 on a z800 (not an 890) which supports OS/390 through z/OS 1.13. They (the z/800's) are still readily available, but it doesn't really place them anywhere for a step up from there because the newest software they can run on the z800 is z/OS 1.13. It would however allow them to run both OS/390 and z/OS on the same physical processor, but it's not the way I would plan the conversion, there are too many places to get caught up in wasting a lot of time. VM is actually not a good idea for them either unless they want to remain at OS/390 for a long time and don't plan on EVER moving up to z/OS. They are probably paying more to run OS/390 than they would for z/OS so they should have an incentive to migrate. There are some known (solvable) issues with running OS/390 under z/VM (they have to use an "older" version), and if they have not converted from OS/390 to z/OS by now, I doubt they will look favorably on z/VM and the people-training time to get to that point, (and keep it there), and the costs will still be much higher for OS/390 on the larger box plus they will have to add the cost of z/VM and new hardware (DASD etc.) on top of that. It's a lot more money than almost any other alternative, and takes longer to implement as well. Probably, the next (and cheapest step) for them is the one I have performed several times in the past, which is to install a new little box (in this case the cheapest "new" box would likely be a z13s which would give them better pricing overall for the first 3 years and maintenance for the hardware is free as well for a couple years which should sound nice to them after what they probably pay to keep their old machine running now) and convert directly from OS/390 2.5 to z/OS 2.2 (or 2.3). The above assumes they have DASD that will allow them to connect to the z13s 2965-N10 (single processor A01 at about 10MSU (~80MIPS)), if they are running with internal DASD or direct ESCON DASD (which they probably are) then the best bet is either replace it (not that costly if they don't go brand new and get one that supports ESCON and FICON, or get a used/new converter) or get a used z114 instead of the z13s (there are actually several viable alternatives that could make sense depending on their current hardware). The cost for the z114 is lower than the z13s, but they won't get the reduced cost for the software and the hardware maintenance would be cheaper than now, but a z13s would be free for maintenance at first. When you compare the total cost over a couple years, the z13s tends to be a better cost-wise alternative, not to mention that it's going to be able to support them for quite a while with anything IBM decides to change to. The process is fairly painless and I typically have the new OS installed in about a week, (3 if you count the two week order time from IBM) and the conversion from OS/390 to z/OS (probably 2.2 in this case) is normally between 30 to 90 days, depending on how much they are using/depending on home-grown exits and how many things (exits, mods, zaps, etc.) I have to reproduce without existing source code. It's fairly easy and painless for the client, but that's probably because I have done this type of conversion many times already so there aren't really many surprises for me any more. The biggest issue (for EVERYONE) is when they have old "vendor" software from places that simply don't exist any more and the software doesn't support new(er) levels of the OS. In cases like that I have a (really) long list of just about every vendor product and how to get them to "work" under newer OS versions. In some cases I have had to dumb down z/OS or create an environment under z/OS that mimics the older runtime code, but I have found that there is (almost) always a way to make it work safely. Some products are just harder than others to get them settled down, but having done this a lot of times, I have all of the tricks and alternatives so there aren't many unknowns. If they are dead-set to stay as OS/390 2.5, then a z/800 is pretty much their only existing choice. Running on a emulator is another option, but the long term viability of that choice is at risk because IBM can (and will at some point in the not distant future) come down on the people (and their customers) for running the emulation of their hardware. IBM has already served notice to two of the places, (that I know about) that they have to stop "production" work. Apparently they have no problem with development or people designing software for home/hobby use, but when you start wanting to run a commercial site they take a very dim view of that. No one wants to have their company come in one morning and be told that IBM pulled the plug on their solution and they have to come up with a LOT of money to not only convert their system, but defend themselves in court. It's not like those places are running plug compatible hardware. Emulators (while they work VERY well) are bad news when it comes to long term viability, (and staying out of court). If you need help or have questions, feel free to ask, or contact me offline. Brian Westerman ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
