Running DB2 AIX on a large p570. Using DS4800 with approx 12TB of disk attached (configured as RAID5). The 570 is not LPARed - one AIX image. Currently there are two HBAs in the 570 connecting via optical fiber to DS4800. Would like to add another two HBAs. Not sure if this can be done/supported. Any ideas? Thx

If there is a limitation, I don't see where that would have anything to do with DB2. Isn't that a P series or AIX question?

According to IBM, two is the limit (per AIX image). On the back of DS4800 there are only 2 sets of 4 outlets for fiber cables (4 on each of 2 controllers). The HBAs themsleves come in 2Gb/s or 4Gb/s flavors. Some red books hint that four is also possible (http://www.db2topgun.com/misc/DS4000...ning_Guide.pdf - see figure 11-10 and text nearby). Yes, I know - never believe anything you read in a red book. But, when they tell you what you want to hear, perhaps we can make an exception Anyway, that is the reason for my question - to find out if anyone tried this. As for whether this is a "P series or AIX question", I have not seen an AIX application that would care about this until DB2 with DPF gets into the picture - no AIX application, that I have seen, is written to drive enough I/O to worry about bottlenecks having to do with HBA bandwidth. So the questions remains, has anyone seen 4 HBAs serving one AIX image?

P.S. BTW, Marcus, if by saying "P series or AIX question" you meant that it does not belong in this forum, feel free to not respond, and let others. Thanks

You asked "Not sure if this [more than two HBAs] can be done/supported".

My answer was, and is, that there is no DB2 limitation or restriction on number of HBA's. So whether it can be done, or if it is supported, is purely an AIX or P-series hardware issue. DB2 does not care.