Yesterday, EMC announced the purchase of Bus-Tech, their partner in mainframe or System z attachment for the Disk Library Mainframe (DLm) product line.
The success of open systems mainframe attach products based on Bus-Tech or competitive technology is subject to some debate but it’s the only inexpensive way to bring such functionality into mainframes. The other, more expensive approach is to build in System z attach directly into the hardware/software for the storage system.
Most mainframer’s know that FC and FICON (System z storage interface) utilize the same underlying transport technology. However, FICON has a few crucial differences when it comes to data integrity, device commands and other nuances which make easy interoperability more of a challenge.
But all that just talks about the underlying hardware when you factor in disk layout (CKD), tape format, disk and tape commands (CCWs), System z interoperability can become quite an undertaking.
Bus-Tech’s virtual tape library maps mainframe tape/tape library commands and FICON protocols into standard FC and tape SCSI command sets. This way one could theoretically attach anybody’s open system tape or virtual tape system onto System z. Looking at Bus-Tech’s partner list, there were quite a few organizations including Hitachi, NetApp, HP and others aside from EMC using them to do so.
Surprise – Mainframe data growth
Why is there such high interest in mainframes? Mainframe data is big and growing, in some markets almost at open systems/distributed systems growth rates. I always thought mainframes made better use of data storage, had better utilization, and controlled data growth better. However, this can only delay growth, it can’t stop it.
Although I have no hard numbers to back up my mainframe data market or growth rates, I do have anecdotal evidence. I was talking with an admin at one big financial firm a while back and he casually mentioned they had 1.5PB of mainframe data storage under management! I didn’t think this was possible – he replied not only was this possible, he was certain they weren’t the largest in their vertical/East coast area by any means .
Ok so mainframe data is big and needs lot’s of storage but this also means that mainframe backup needs storage as well.
Surprise 2 – dedupe works great on mainframes
Which brings us back to EMC DLm and their deduplication option. Recently, EMC announced a deduplication storage target for disk library data used as an alternative to their previous CLARiion target. This just happens to be a Data Domain 880 appliance behind a DLm engine.
Another surprise, data deduplication works great for mainframe backup data. It turns out that z/OS users have been doing incremental and full backups for decades. Obviously, anytime some system uses full backups, dedupe technology can reduce storage requirements substantially.
I talked recently with Tom Meehan at Innovation Data Processing, creators of FDR, one of only two remaining mainframe backup packages (the other being IBM DFSMShsm). He re-iterated that deduplication works just fine on mainframes assuming you can separate the meta-data from actual backup data.
System z and distributed systems
In the mean time, this past July, IBM recently announced the zBX, System z Blade eXtension hardware system which incorporates Power7 blade servers running AIX into and under System z management and control. As such, the zBX brings some of the reliability and availability of System z to the AIX open systems environment.
IBM had already supported Linux on System z but that was just a software port. With zBX, System z could now support open systems hardware as well. Where this goes from here is anybody’s guess but it’s not a far stretch to talk about running x86 servers under System z’s umbrella.
So there you have it, Bus-Tech is the front-end of EMC DLm system. As such, it made logical sense if EMC was going to focus more resources in the mainframe dedupe market space to lock up Bus-Tech, a critical technology partner. Also, given market valuations these days, perhaps the opportunity was too good to pass up.
However, this now leaves Luminex as the last standing independent vendor to provide mainframe attach for open systems. Luminex and EMC Data Domain already have a “meet-in-the-channel” model to sell low-end deduplication appliances to the mainframe market. But with the Bus-Tech acquisition we see this slowly moving away and current non-EMC Bus-Tech partners migrating to Luminex or abandoning the mainframe attach market altogether.
[I almost spun up a whole section on CCWs, CKD and other mainframe I/O oddities but it would have detracted from this post’s main topic. Perhaps, another post will cover mainframe IO oddities, stay tuned.]