How to flush the dirty pages to disk in SQL Server
Pages which are modified and are residing in memory are called as Dirty Pages. These pages needs to flushed to DISK at regular intervals.
Checkpoint command usually flushes the data from dirty pages to disk (MDF).
Find the number of dirty pages in each database by executing the below query:
SELECT db_name(database_id) AS 'Database',count(page_id) AS 'Dirty Pages'
For flushing the data to disk issue
CHECKPOINT
Above command can be issued by the account having SA privileges.
Hope the above information helps
Thanks