DS8000 value
Overall Satisfaction with IBM System Storage DS8000
We use the DS8000 at many of our customers. I have several of them installed at customers who work in financial markets. Typically, I see it used in Mainframe only environments, due to the relative cost of the DS8k compared to the variety of platforms available for open systems environments. However, even now I have some customers who have open systems environments connected to DS8000 when it is an extremely high priority environment that cannot afford downtime.
Primarily I see it used for FICON attachment. The reason for that is pretty simple -- IBM works very closely between their storage and z groups to maintain "synergy". But it's also just a rock solid highly available platform that's become more reliable with time.
Additionally, when it comes to business continuity functions it can be pretty incredible. Its Global Mirror function particularly impresses me. It's able to deal with exceptionally high latency and still deliver single-digit seconds of RPO (in extreme cases this might require development to use "pokeables"). When combined with Copy Services Manager or GDPS, it really brings disaster recovery functions to a very usable level for the enterprise.
Primarily I see it used for FICON attachment. The reason for that is pretty simple -- IBM works very closely between their storage and z groups to maintain "synergy". But it's also just a rock solid highly available platform that's become more reliable with time.
Additionally, when it comes to business continuity functions it can be pretty incredible. Its Global Mirror function particularly impresses me. It's able to deal with exceptionally high latency and still deliver single-digit seconds of RPO (in extreme cases this might require development to use "pokeables"). When combined with Copy Services Manager or GDPS, it really brings disaster recovery functions to a very usable level for the enterprise.
- Remote Copy -- The DS8k has decades of excellent code built to handle the most demanding environments for mainframe or open systems and can be combined with automation solutions like GDPS or Copy Services Manager
- Reliability and Availability -- This is the platform that gets used for the most demanding environments, even when FICON attachment isn't required
- Continued enhancement -- IBM continues to put resources into the DS8k and the platform has advanced with the technology from z and power
- Mainframe synergy -- Poughkeepsie communicates and works very closely with the DS8k developers
- Data Reduction -- DS8k doesn't do any. If you're running a mainframe with pervasive encryption turned on, that's not an issue but it could be for many distributed environments
- FlashCopy -- based on Copy on Write. It works well, but it would be nice to see it move to something like Redirect on Write
- Expense -- What can I say? It is more expensive than most people in an open systems environment are willing to pay when compared with offerings that don't have FICON
- I've worked with a focus on DR for a long time, and the DR options in the DS8k have been impressive the entire time
- zSynergy features have helped my customers make more effective use of their environment
- The fact that it can use both FICON and FCP has provided flexibility for those customers I have who really do need both at that level of availability
I find that I still prefer to recommend the DS8k unless a customer is very committed to EMC, which does sometimes happen. Global Mirror has always been a much stronger replication platform than SRDF/A, capable of maintaining much better RPOs. But it's really the relationship that IBM is able to maintain between z and storage development teams in IBM. The mainframe is a pretty specific environment and it's important to have what IBM brings to the table