A prior student emailed me yesterday about some strange behavior of the sample_ms column in sys.dm_io_virtual_file_stats. It’s supposed to be the number of milliseconds since the SQL Server instance has been started. He has a SQL Server 2016 instance that’s been running since August 2019, and it shows the following:
– ms_ticks from sys.dm_os_sys_info: 51915112684 (which works out to be August 28, 2019)
– sample_ms from sys.dm_io_virtual_file_stats: 375504432 (which works out to be about 4.5 days)
Read on to get a determination and an alternative in case you’re using that field.