I was using perfmon to monitor writes per second on a LUN containing a single SQL2005 database data file. I was under the assumption that database files are only written to during checkpoints or by the lazy writer process, is this assumption correct? as something seemed to be writing to the LUN when the checkpoint and lazy writer processes were inactive.
The writes seem to happen every 3 seconds or so and is 510 bytes long? I have my suspicions that it's not SQL writing to the LUN but some OS process.
This write is actually hitting all my LUNs simultaneously - so can't be SQL.