无法删除FileStream FileGroup或将其重新附加到SQL Server数据库

Question

Background: I had a working SQL Server Database created in SQL 2010, with 2 different FileStream/FileGroups, working fine. I detached the database, moved it to another desktop with SQL 2016 (on Win 10 Pro), and manually copied the 2 Filestream folders (called ImageFS and DocFS ). I simply re-attached the mdf database and didn't pay attention to the Filestream functions because it wasn't being used. Months later I noticed that one FileGroup/Fileshare (ImageFG/ImageFS) works fine, and the other one ( DocFG/DocFS ) doesn't. In more detail, this is what I get

SELECT DocFileID, ModifiedDate FROM DocFile
-- WORKS FINE

SELECT DocFileID, ModifiedDate, Doc FROM DocFile
--Returns this error:
-- A transport-level error has occurred when receiving results from the server. (provider: Shared Memory Provider, error: 0 - No process is on the other end of the pipe.)

So, Doc is the filestream field in this table. I tried to remove the field and add it again, but SSMS won't let me:

ALTER TABLE DocFile DROP COLUMN Doc
--Returns this error:
-- The FILESTREAM filegroup '**DocFG**' has no files assigned to it. FILESTREAM data cannot be populated on this filegroup until a file is added.
-- Huh?  there are already files in this Windows folder

I also tried to shrink the DocFG filegroup to try to delete it but I get this error.

DBCC SHRINKFILE ('DocFG', EMPTYFILE)
--Returns this error:
--Could not locate file 'DocFG' for database 'MyDB' in sys.database_files. The file either does not exist, or was dropped.

I have tried to detach and reattach the database, using this code, but it doesn't make a difference:

CREATE DATABASE [MyDB]
 ON  PRIMARY 
( NAME = N'MyDB', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL13.SQL2016\MSSQL\DATA\MyDB.mdf' , SIZE = 71040KB , MAXSIZE = UNLIMITED, FILEGROWTH = 10%), 
 FILEGROUP [ImageFG] CONTAINS FILESTREAM 
( NAME = N'ImageFS', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL13.SQL2016\MSSQL\DATA\ImageFS' , MAXSIZE = UNLIMITED), 
 FILEGROUP [DocFG] CONTAINS FILESTREAM DEFAULT
( NAME = N'DocFS', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL13.SQL2016\MSSQL\DATA\DocFS' , MAXSIZE = UNLIMITED)
 LOG ON ( NAME = N'MyDB_log', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL13.SQL2016\MSSQL\DATA\MyDB_log.ldf' , SIZE = 43264KB , MAXSIZE = UNLIMITED, FILEGROWTH = 10%)
FOR ATTACH

This ataches fine, but DocFS/DocFG still doesn't work. I also tried to use SSMS to manually "REMOVE" DocFG, but I get an error as well:

SSMS1

SSMS2

Any thoughts about where to proceed with this?

Answer 1

It turns out that this was an oddball situation. Somehow the DocFS (files tab of Database properties) and DocFG (filegroups tab of Database properties) were not in sync (for lack of a better term). If you tried to re-create the DocFS based on DocFG, SSMS wouldn't let you. The reason being that the original corresponding Windows directory was already there, and SSMS was trying to recreate one there.

Solution (for me, at least):

1. Rename the windows directory ("...\\DocFS" in my case), to something temporary, such as "..\\DocFS_Temp\\")
2. go back and re-create the DocFS "file" in the files tab of Database Properties, being sure to select the corresponding FileGroup (eg DocFG). This will then create a new "...\\DocFS" Windows directory
3. Delete this newly created "...\\DocFS" Windows directory
4. Rename the temp directory back to "...\\DocFS"

Other housekeeping things I did (which may or may not have helped) ...I toggled the DB offline, and then back online. I also had to toggle the auto-growth from unlimited to 10% and back to shake off a "directory is full" error.

I hope this helps someone else.