So in SQL Server 2008 and beyond what do the columns numberReads and numberWrites mean? I thought this was simply the number of reads the number of writes issued by the sqlserver.exe process. I went to test this idea and pulled up process explorer on a test machine. I ran a simple backup that netted 10 reads and 16 writes in the database I backed-up and as well as 1 write in the tempdb log, 1 write in the msdblog, and 4 writes in the mastlog according to the fn_virtualFileStats. (10 total reads 22 total writes) According to process Explorer the SQLServe.exe process issued 16 reads and 46 total writes. Now my guess is the SQLServer.exe had to write to the new backup file and that could account for the number of write differences. What accounts for the number of read differences? Does the SQLServer.exe process read the new backup file while/after it creates it?
I'm looking to make sure I understand the information displayed in fn_virtualFileStats, I always tookthe numberReads and numberWrites to be a measure of IO, is this incorrect?
Thanks ahead of time,
Steve