Have a SQL Server 2014 instance running on Windows 2012 R2 that was running Ola Hallengren's DB integrity script. This is the error that resulted:

The operating system returned error 665(The requested operation could not be completed due to a file system limitation) to SQL Server during a write at offset 0x0001392f6ee000 in file 'H:\MSSQL12\Data\EDW_Data_6.ndf_MSSQL_DBCC15'. Additional messages in the SQL Server error log and system event log may provide more detail. This is a severe system-level error condition that threatens database integrity and must be corrected immediately. Complete a full database consistency check (DBCC CHECKDB). This error can be caused by many factors; for more information, see SQL Server Books Online.

I checked both the event log and the SQL Server error log but not getting a lot of additional info that could help. I haven't rerun the DBCC check for this db yet. This database is pretty active as it is a data warehouse database. It's currently 10.5 TB. I've heard that if I rerun the dbcc it may clear out the MSSQL_DBCC15 however I'm hesitant to do that on this server due to the level of activity. My preference would be to copy the backup to another server and run the dbcc there. If I do that, is there any way for me to clean up the DBCC15 files left on disk on the primary server?

Any other places I could find more info other than event log and SQL Server error log?

Appreciate any thoughts on what could cause this error or the best option for running DBCC checkdb based on the situation.

  • Does the file still exist? And what makes your situation special? This is a fairly well-known issue. Solutions can be found by Googling the error message.
    – usr
    Apr 6, 2015 at 10:00
  • Yes, the file still exists -- there are 8 of them. When I've seen these errors on other servers in the past, they haven't left the DBCC15 files on the filesystem. They've been cleaned up when the integrity check failed. In this case they were not cleaned up and still exist taking up a lot of disk space. I have googled the error but I didn't see anything similar where the files didn't get cleaned up.
    – Toni
    Apr 6, 2015 at 14:45

1 Answer 1


DBCC creates a database snapshot, and database snapshots are implemented using NTFS sparse files. Error 665 reported for DBCC has been reported before, and blogged about by the CSS team, read:

The articles linked show the problem details, and the applicable fix (depends on your OS version and configuration).

  • I don't have any stack dump files to analyze. Can the DBCC16 files be deleted or do they need to be cleaned up by rerunning the integrity check with one of the options mentioned in the links?
    – Toni
    Apr 6, 2015 at 15:05
  • @Toni you can delete them. If you really want to be sure, rename them and let them sit for a few days.
    – usr
    Apr 6, 2015 at 15:32
  • Yes, I will rename one of them and see what happens. At least I have a backup to go to in the event something goes awry. Thank you.
    – Toni
    Apr 6, 2015 at 16:01

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