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I agree with what you are saying. However we were running the 12 x 6718 on the 2778 both before and after the upgrade. The load source in on one of the 6718's. Really nothing changed DASD wise except to remove the other 30 drives in the old migration tower. But then they have not been used for the last 4 weeks. We marked them as read only and then to remove the data. ASP BAL brought them to around 1% usage with really no read/writes. Besides there are only 6 drives on a chain and two chains on the 2778. Doing a WRKDSKSTS does not show any abnormally high usage. What would you second guess be? -----Original Message----- My first guess would be the 2778 and 6718s are holding you back. Their cache & disk speed pale in comparison to the new stuff. The controller in particular as the 2778 has 26MB write cache and no read cache vs. the 2780's 1GB write & 757MB (w/compression) read caches. Cache can make a huge difference. Also, the 2778/6818 are 80MB/sec SCSI while the 4326s are 160MB/sec. Not an issue for an individual drive as modern single drives don't sustain that high of a transfer rate but the 80 & 160MB numbers are the max combined for the entire chain. Other factors would include: - differing drive sizes/platter densities between the 18 & 35GB disks - PCI vs. PCI-X buses in the drawers - 10K vs. 15K makes a difference in latency. - system RAM; was it increased? Are pool allocations comparable? - if the old system was CPU/RAM-contrained, you may have also been DASD-constrained but just not known about it. With CPU raised, it's possible you eliminated one constraint just to bump in to another. Unless you're using multiple ASPs to isolate your production files to the 15K drives & new controllers, your older tech is very likely holding you back.
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