On Tue, 2009-06-23 at 15:21 +0200, Bohmer, Andre ten wrote: > ]# vmstat 1 > procs -----------memory---------- ---swap-- -----io---- --system-- > -----cpu------ > r b swpd free buff cache si so bi bo in cs us sy id > wa st > 2 10 110012 90012 8012 2934768 1 0 2797 237 3 2 10 1 80 > 9 0 > 2 10 110012 125728 8024 2897996 0 0 96560 44 7027 7927 22 3 33 > 42 0 > 1 10 110012 101376 8072 2922136 4 0 73452 36 6834 7377 22 3 46 > 29 0 > 2 9 110012 110076 8040 2913072 0 0 118236 96 7716 8594 22 3 43 > 31 0 > 1 10 110012 104080 8112 2919176 0 0 84912 7880 7096 7920 19 3 37 > 41 0 > 1 10 110012 92572 8076 2931128 0 0 96220 48 7225 8276 24 3 32 > 42 0 > 2 9 110012 112192 7996 2911412 0 0 99088 148 7444 8531 21 3 44 > 32 0 > 4 7 110012 97496 8040 2926508 0 0 86388 60 7475 8212 22 3 44 > 31 0
That output certainly shows a system that is doing a lot of read I/O, but I wouldn't describe that as an I/O "problem". This output shows that your system is reading nearly 100,000 blocks/sec which, probably 50MB/sec, which, if it's Oracle single block sequential reads, and based on the number of spindles your running against, may or may not be all that bad as, assuming spinning platters (i.e. not SSD) your sequential block reads are typically limited by the number of IOPS your array will produce, not by it's throughput. > Server is a HP Prolaint Blade BL460C with 2 FC-HBA's, dual quad core en 16GB > memory. > > Any input is welcome about how to improve IO performance or how to determine > why IO is the bottleneck. Well, I think we would need more data. What is the wait profile of the Oracle query you are running? What is the size of the data set? Is it expected to fit within the Oracle block cache? How big is the Oracle SGA/block buffer cache? How many spindles and what type of disk make up the storage? Can you give us some output of 'iostat -x' while a query is running? Later, Tom _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
