SQLServer uses it from version 2005 til 2012 to create databases snapshots in order to run DBCC CHECKDB (consistency check). So for actually a critical feature

SQLServer uses it from version 2005 til 2012 to create databases snapshots in order to run DBCC CHECKDB (consistency check). So for actually a critical feature of MSSQL. I suppose this was the reason why ReFS was not supported for SQL data disks. It seems they are not used anymore since sql 2014. See for example http://www.sqlskills.com/blogs/paul/issues-around-dbcc-checkdb-and-the-use-of-hidden-database-snapshots/ http://www.sqlskills.com/blogs/paul/issues-around-dbcc-check...