SAP on IBM i – Update week 48 2013: Availability IBM i 7.1 TR 7
On November 15th 2013, IBM i 7.1 technology refresh 7 became generally available. It can be ordered from IBM as PTF group SF99707. For an overview of the new features and enhancements in TR7, see the announcement letter at IBM i 7.1 Technology Refresh 7 offers performance, usability, and integration enhancements. More detailed technical descriptions can be found at IBM i Technology Updates.
If you are running SAP on IBM i, the following enhancements may be of special interest for you:
- IBM i 7.1 Technology Refresh 7 offers support for several new hardware features, such as solid-state drives (SSDs). For a complete list, see the anouncement letter that we link to above.
- The maximum size of an SQL index has been increased to 1.7TB. Non-partitioned tables could already grow up to 1.7TB, but for indexes, the size was still limited to 1 TB. This limit has now been increased.
- Phase 2 of the tracking of important system limits has been shipped. In our blog entry of October 25th 2013, we had already announced that: SAP on IBM i – Update week 43 2013: Proactively monitoring table size limits on IBM i. The following article provides a very good and detailed overview over the concept: OnDemand Tracking of Important System Limits on IBM i. In the meantime we found out, that you will only see an entry with SIZING_NAME = ‘MAXIMUM NUMBER OF VARIABLE LENGTH SEGMENTS’ in view QSYS2/SYSLIMITS if you have a table that actually has more than 100 variable length segments. So if you don’t see such an entry after applying the technology refresh, do not worry: You just don’t have a table that is coming close to the critical limit.
The database enhancements in IBM i 7.1 technology refresh 7 are mostly available through DB2 PTF group SF99701 level 26 as well. Those enhancements will also be made available for IBM i 6.1 through DB2 PTF group SF99601 level 31, which is scheduled to become available on December 6th 2013. However, other features of IBM i 7.1 TR7, in particular the support of certain hardware components, may not become available for IBM i 6.1 at all.
To me this TR brings a couple of excellent items for BW performance.
In addition to the larger index size Christian mentioned, the TR introduces the SW OS drivers for the latest IO enhancements...
the new small form factor 387 GB and 775 GB solid-state drives (SSD) - and the PCIe2 1.8 GB Cache RAID SAS Adapter to drive them. The larger cache is great!
With larger capacity SSD drives and the new adapter, it is that much easier to simply run entire LPARs with ALL SSD. Number of disk arms (units) are less and less important. With the new HW it's almost just a matter of getting the minimal number of IOAs to support the minimal number of SSDs to meet your capacity requirement.
I tend to disagree with Ron. While the speed of SSD's will certainly affect how many units may be required, I would stray away from simply buying for capacity. You're still going to create unnecessary bottlenecks for the disk intensive environments (which is happening more and more often). Also, the technology is still relatively expensive to purchase only SSD's except for the smaller shops...
There are still very good, solid reasons to buy more smaller SSD's rather than fewer larger SSD's. You're still going to be forcing data syncronously - it will be faster to spread that over multiple units than down one.
In otherwords - while SSD's are faster than traditional disk units - they are still slower than the system.
Be very cautious about buying to capacity with or without SSD's.
Thank you Rocky, I agree with you. It is still possible to have too few units, given a very heavy IO workload. It's much harder than with HDD and the first gen SSDs, but still possible. One should still do a proper sizing and not just go for a certain capacity. I said it "almost just a matter of getting the minimal"... I should have been clearer.
The thought to take away is that enterprise SSDs have had a few generations to evolve.
Current enterprise SSDs are significantly bigger, faster and cheaper than when they first came out.
We are definitely seeing most customers taking advantage of them in some way, and it's reached the point where we are seeing increasing numbers just deciding for all SSD configurations.