I got dedicated disk (RAID 10 - 4 SAS disks) for Postgres. I am bit worried as recently, I see under Windows Resource Manager disk queues like 3+ in the mornings (low traffic hours), like every 30-60 seconds. I checked what queries are running, started logging queries 1000ms+ but I cannot see what is causing this traffic. It looks like transaction log is saving most data, but I've read xlog to another disk will only give max 20% performance gain. I was thinking about some triggers added recently, but I am not sure how to check it.
Can you give me any tips how to find what is causing this traffic?