I'm having a hard time figuring out why my app can't access filestream data, after we enable AG listener.

Background info:

Initial environment:

APP Server

Web Server IIS Windows Server 2012 R2

DB Server

Windows Server 2012 R2

SQL Server N1 (named instance N1\SQL2016 port 1434) with DB (APP_DB) (with filestream data). Filestream I/O enabled, filestream data was available to APP (web application (IIS)) - read write OK

Environment changes:

Add new server Node 2 (N2) installed same SQL Server version as default instance

Create failover cluster CL (N1 + N2)

Implemented Always On (DB replication working)


When AG listener is created the filestream data is accessed over the VNN name (equal to Listener name) (\VNN\filestream_share_name) and the app can't access the data over the new path.

When accessing N1 or N2 over file explorer \N1\ we can see the filestream share name, but when accessing the VNN name (\listener) in file explorer we can't see the sql server filestream share name.

I have tried to disable and disable / enable filestream I/O on both SQL Server nodes, to recreate the VNN\filestream share name, but no success.

  • 1
    From where are you trying to access the VNN fileshare? Have you checked that any firewalls are allowing the filesharing ports (139 and 445) on the Listener IP(s)?
    – AMtwo
    Sep 21, 2021 at 3:36
  • When accessing the location \\N1\filestream_share_name with file explorer (access from APP server), we can access the location. \\VNN\filestream_share_name (vnn = listenername) is not visible when accessed from app server. Can we somehow verify the existence of the \\VNN\filestream_share_name location ? Sep 21, 2021 at 19:55
  • Have you checked to see if ports 139 & 445 are being blocked by a firewall?
    – AMtwo
    Sep 21, 2021 at 22:49
  • Ports 139 and 445 are open, verified by network admin. Sep 22, 2021 at 10:15
  • Have you tried it when the new node is hosting the database? Are the symptoms the same regardless of which node is hosting the database? Are the files on shared storage?
    – Hannah Vernon
    Oct 4, 2021 at 13:28


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