Am trying to troubleshoot performance on an SQL server that we have for our document management server and today performance has hit an all time low. Looking at the MDW I setup recently I can see a huge spike in the Buffer I/O. The combined SQL Wait time is in the region of 1500-2000 ms which is considerably higher than normal (around 500ms). The large proportion of this increase is Buffer I/O.
Not being a DBA and doing this out of neccessity I am massively out of my depth. Is there any way to tell why there has been a large increase in buffer i/o? Is this likely due to a query pulling large amounts of data or incorrect config of sql memory limits? Is there anything specific (or general for that matter) I should be looking at or DMVs I can query to help troubleshoot?
The server is 2008 R2 as is SQL. It is a VM running two vCPUs and 8GB RAM with the disks hosted on a separate array on a SAN.
EDIT: I think I may have misread this graph on the server. I actually think it is Lock Wait that has increased dramatically not Buffer I/O. The colours are far too similar for me to pick out at a glance :(