Informix 7.24 with SAP R/3 : EMC2 : striping / fragmentation

We plan to move our Informix databases to an EMC2 3700 box in the near future. Our production database and also our two Q&A databases (both are regularly "overwritten" by our production database) are around 250 GB. Our production database is currently growing with 3 GB/week. The databases are only used by SAP R/3, so there are no DSS-queries. SAP R/3 never uses sequential scans for the larger tables, so all accesses are done by using one of the available indexes. The EMC2 3700 box can contain 128 disks of 47 GB or 18 GB and currently has 4 GB cache. Our database server is a SUN E6000 with 14 CPUs and 4,5 GB of RAM. The disks (47 GB disks for the Q&A databases and probably 18 GB disks for production later on) are split into multiple logical disks (called hypervolumes) of 4 GB. Mirrorring is done by the EMC2 3700 box (so mirrorring is not done by using Informix or some volume manager). A technical guy from EMC2 recommended us to simply define two raw devices of 2 GB per logical disk (and as such not use any striping). [The Symmetrix uses pre-fetching to put tracks in it's big cache.] I have also recently started to fragment some of the big tables (> 20 GB). Fragmentation is done by round-robin as recommended by SAP. I was always in favor of striping data over multiple disks to avoid over-loaded disks, so I am now worried that I could get bottlenecks. QUESTION : ---------- Do any of you have a large OLTP environment with EMC2 and Informix ? If so, did you use disk striping or did you fragment database tables ? Any opions about striping and round-robin fragmentation with EMC2 HW ? Thanks in advance, Mario Opsomer Informix DBA - SAP BC Support