Solarwinds Orion’s interaction with the SQL server is extremely disk write intensive and requires a fast storage sub-system on the supporting SQL server.  RAID 10 is the fastest disk configuration with redundancy. Having a fast controller with write cache also increases performance. I use a tool called SQLIO.exe to test the write speed of the SQL storage system hosting the log files and tempDB. It can be downloaded from Microsoft.com.  This tool performs controlled disk read/write operations and is used to gauge the storage system IO performance.  The higher the number, the better the performance. There are dozens of options for SQLIO.  I run general write performance tests on the SQL log file drive. A score of 800 or higher will do for most installations. I’ve seen throughput as high as 7000 IOP’s on solid-state drives.  There is no reason you cannot install SQL on a virtual machine using a SAN as long as you can get acceptable IOP performance. Click the image to the right. This is the new AppInsight application monitor contained in Solarwinds Server and Application Monitor (SAM) 6.0.

Refer to this Solarwinds White paper for SQL tuning guidance  PDF – Managing Orion Performance