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MS-SQL backup fails with "SQL30 – Failed to create the IOClient connection" due to missing vcruntime140.dll

MS-SQL backup fails with "SQL30 – Failed to create the IOClient connection" due to missing vcruntime140.dll

Problem description

MS-SQL backups fail shortly after initiation with the error message: SQL30 – Failed to create the IOClient connection.

This issue occurs during the backup initiation phase when the Phoenix backup agent attempts to start and establish a local connection with sql-ioserver.exe. If the server environment lacks necessary runtime dependencies or if security software terminates the process, the connection times out and the backup aborts.

Cause

The process sql-ioserver.exe fails to initialize or crashes immediately upon execution because the required Microsoft Visual C++ runtime file vcruntime140.dll is missing from C:\Windows\System32\.

(Note: In some environments, aggressive antivirus/endpoint protection software blocking or terminating sql-ioserver.exe or sql-client.exe can present the exact same symptom and timeout error.)

Traceback
In sqlclient_plugin_job.log:

level=info ... message="Connecting to SQL IOServer" ServerURL=127.0.0.1 ServerPort=20025 level=error ... message="failed to create the IOClient connection." ServerURL=127.0.0.1 ServerPort=20025 Error="context deadline exceeded"

In the Windows Application Event Log (Event ID 1000):

Faulting application name: sql-ioserver.exe Faulting module name: vcruntime140.dll, status: 0xc0000135 (Unable to Locate DLL)

Resolution

Step 1: Restore the missing runtime library

  1. Navigate to the local Druva Enterprise Workloads directory:C:\Program Files\Druva\EnterpriseWorkloads\lib\fs

  2. Locate vcruntime140.dll and copy it to:C:\Windows\System32\(Alternative: Download and install the latest official Microsoft Visual C++ 2015–2022 Redistributable (x64) package on the host).

Step 2: Ensure Antivirus/EDR exclusions are configured

Ensure the following Druva executable processes are excluded from real-time monitoring and endpoint inspection to prevent process termination:

  • mssql.exe

  • sqldiscovery.exe

  • PhoenixSQLAgent.exe

  • PhoenixSQLGuestPlugin.exe

  • PhoenixSQLDownloader.exe

  • PhoenixSQLUploader.exe

  • sql-ioserver.exe

  • sql-client.exe

  • drst-ioserver.exe

Verification

  1. Trigger an on-demand manual backup of the affected MS-SQL database from the Druva Management Console.

  2. Confirm that sql-ioserver.exe starts and remains active in Windows Task Manager during the job.

  3. Verify that the backup job transitions through the snapshot and data transfer phases without reporting SQL30, completing with a status of Successful.

  4. Monitor subsequent scheduled backups to ensure consistent execution.

See also

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