Adding IBM Mainframe to DMX

Question

Currently we have 2 DMX1000s that are used for open systems. When we get our new DMX4 arrays we will port our open systems but will also connect our IBM mainframe (currently connected to Shark).

On the open systems side we will likely use split sizes of around 8GB. The mainframe is a source of confusion regarding split size. I believe we use mostly mod3 and mod9s on our Mainframe. Maybe mod27s in the future.

I believe that a mod3 is around 2.8GB. I believe a mod9 is three mod3s. A mod27 is 3 mod9s. Should our split size for the MF be 2.8GB? Or should the split size be a subset or fraction of the 2.8 for example use four .7GB slices to make up one mod3 (.7 * 4 = 2.8)? This would make sure that every mod3 would be spread across 4 disks.

Anyway, I'm not too sure how much of the open systems stuff translates to the MF stuff so any help would be appreciated.

Thanks - Brad

brad12341 · Answer

A little more info. On the open systems side we typically have large file systems or Windows partitions. An AIX file system may be 22GB. In this case we would likely use a 4-way or 8-way striped meta to get several spindles involved for performance. In SQL server most of our databases are around 130GB. We might use a 16-way or 24-way striped meta. Lots of spindles helps with performance.

On the MF the objects (similar to AIX file systems or Windows partitions) seem to be smaller. If we use a 2.8GB split and the object only needs one then it seems like we would only engage one spindle. Althought the .7GB split size seems extremely small to me it may be the best way to get more spindles involved.

xe2sdc · Answer

Use different HDA for MF and Open .. and live happy

brad12341 · Answer

Does anyone know of some good documentation to help an Open Systems guy understand the symm in a ZOS environment? Maybe something that helps explain ZOS disk environment etc.

In AIX we have file systems, AIX Logical Volumes and AIX Volume Groups. We add symm devices to the AIX Volume Group and then create AIX logical volumes and file systems from the VG.

What do we have on the ZOS side.

xe2sdc · Answer

Brad, there is a 'Mainframe' area in Host Software forums where you can drop some questions .. AFAIK Mainframe is a whole different world, ages ahead of Open System. Just to name one, MF don't need PowerPath, it's already in the 'kernel'. Since 30 years. .. I can ask Dave (owner of the MF area) to jump in .. but I think it's better to open a brand new thread in the (almost) appropriate area

brad12341 · Answer

OK, thanks. I'll go ahead and post the question over there.

Allen Ward · Answer

If you aren't finding what you need over there (especially relating to mixing Open Systems & Mainframe on an array) let me know. I don't pay much attention to the mainframe forums, but I have a mixed environment on DMX3.

I won't pretend to know the mainframe storage world well, but I've picked up a lot from our mf specialists (and they in turn are learning lots from me). I know a lot of the issues we have faced together and how we decided to resolve them.

So, let me know if you want to chat after getting a pure mf perspective (since I'm assuming most of the mf guys are like ours and don't care about the mixing or what OS is doing on the array).

xe2sdc · Answer

Brad already opened a new thread with some questions and ideas in the Mainframe are of the Host Software forums .. Your contribution will be greatly appreciated

Symmetrix

Adding IBM Mainframe to DMX

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