I have been working with DB2 for several years but always on Unix. Several of the db's I am supporting run on Windows 2008 R2, and they all have really poor IO performance. I mean really poor. I set up a sandbox to do some testing and it have been able to replicate the poor performance, which is good since I can test any suggestions anyone comes up with. If I run SQLIO (found on the internet to test IO performance), I get the following:
throughput metrics:
IOs/sec: 9381.73
MBs/sec: 293.17 <-- Not too bad
When I watch this utility run through Resource Monitor I see similar mbs/sec. However, if I run a simple select count(1) on a table, that is only around 1.6 GB with 28 million rows it takes 5+ minutes. My sandbox is otherwise completely idle. Also, my MBs/sec visible thru Resource Monitor is only around 1 MB/sec, compared to the 293 MBs/Sec I see when running SQLIO. Any ideas on where to start? Is there anything special to look at when it comes to DB2 and Windows I/O? I turned off file system caching. I have plenty of memory, no paging but when I look at the disk I am running at 98%.
throughput metrics:
IOs/sec: 9381.73
MBs/sec: 293.17 <-- Not too bad
When I watch this utility run through Resource Monitor I see similar mbs/sec. However, if I run a simple select count(1) on a table, that is only around 1.6 GB with 28 million rows it takes 5+ minutes. My sandbox is otherwise completely idle. Also, my MBs/sec visible thru Resource Monitor is only around 1 MB/sec, compared to the 293 MBs/Sec I see when running SQLIO. Any ideas on where to start? Is there anything special to look at when it comes to DB2 and Windows I/O? I turned off file system caching. I have plenty of memory, no paging but when I look at the disk I am running at 98%.