Virtual File Stats

The cumulative I/O story for every file on the server, straight from fn_virtualfilestats. The first query reports per-file bytes read and written, total and split I/O stall time in milliseconds, operation counts and file size in MB; the second rolls it up to one row per database. (These are cumulative since the last restart - pair with a delta approach for rate measurements.)

SELECT
	DB_NAME(vfs.DbId) DatabaseName,
	mf.name,
	mf.physical_name,
	vfs.BytesRead,
	vfs.BytesWritten,
	vfs.IoStallMS,
	vfs.IoStallReadMS,
	vfs.IoStallWriteMS,
	vfs.NumberReads,
	vfs.NumberWrites,
	(size*8)/1024 Size_MB
FROM
	fn_virtualfilestats(NULL,NULL) vfs
INNER JOIN sys.master_files mf
	ON mf.database_id = vfs.DbId
	AND mf.file_id = vfs.FileId
GO

SELECT
	DB_NAME(vfs.DbId) DatabaseName,
	SUM(vfs.BytesRead) as BytesRead,
	SUM(vfs.BytesWritten) as BytesWritten,
	SUM(vfs.IoStallMS) as IoStallMS,
	SUM(vfs.IoStallReadMS) as IoStallReadMS,
	SUM(vfs.IoStallWriteMS) as IoStallWriteMS,
	SUM(vfs.NumberReads) as NumberReads,
	SUM(vfs.NumberWrites) as NumberWrites
FROM
	fn_virtualfilestats(NULL,NULL) vfs
GROUP BY
    vfs.DbId
GO