How to fix Error 3087 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 3087 – Snapshot Backup Resume Notification

Why This Error Happens

Error 3087 is actually an informational message, not a critical failure—it is logged when a database that was suspended for VSS (Volume Shadow Copy Service) snapshot backup processing is successfully resumed, but the resume operation occurs in a different session ID than the one that initiated the suspension. This typically happens when a third-party backup tool, SAN-based snapshot utility, or VSS requestor loses its original connection handle (due to timeout, connection pooling, or application restart) and a new session issues the “thaw” command on behalf of the database. While the message confirms the database was successfully unfrozen, its appearance signals an underlying instability in the communication channel between the VSS writer and the backup software, which can eventually lead to prolonged I/O freezes if left unaddressed.

Step-by-Step Resolution Guide

Step 1: Verify the VSS Writer and Backup Tool Session Integrity

  • Open Event Viewer and check the Application Log for related SQLWriter or VSS events around the same timestamp as Error 3087.
  • Run vssadmin list writers in an elevated Command Prompt to confirm the SqlServerWriter service state is “Stable” and not “Failed” or “Retryable Error.”
  • Check if the backup software (e.g., Veeam, Commvault, NetBackup) logs show a connection drop or re-authentication event during the snapshot window.

Step 2: Review SQL Server Session Timeout and Connection Settings

  • Navigate to SQL Server Configuration Manager and inspect the network protocol settings for unexpected connection resets.
  • Check the remote query timeout and sp_configure 'remote login timeout' values, as overly aggressive timeouts can force a session restart mid-freeze:
  EXEC sp_configure 'remote login timeout', 0;
  RECONFIGURE;
  • Ensure the backup agent is not configured to use connection pooling for the VSS freeze/thaw session, as pooling can silently swap session IDs.

Step 3: Update SQL Server VSS Writer and Backup Agent Components

  • Confirm SQL Server 2025 has the latest Cumulative Update applied, as session-handling fixes for SQLWriter.exe are frequently included in CU patches.
  • Reinstall or repair the SQL Server VSS Writer service via:
  net stop SQLWriter
  net start SQLWriter
  • Update the third-party backup agent/connector to the version certified for Windows Server 2025 and SQL Server 2025, as legacy VSS requestors are a common cause of session mismatches.

Step 4: Increase Snapshot Freeze Threshold (If Using SAN-Based Snapshots)

  • If using hardware VSS providers (SAN-level snapshots), increase the I/O freeze timeout in the SAN provider configuration (default is often 10 seconds, which can be too short for large databases).
  • Locate the provider-specific registry key or configuration file (varies by vendor, e.g., Dell, NetApp, Pure Storage) and extend the freeze window to 30–60 seconds to allow the original session to complete the thaw without re-authentication.

Alternative or Verification Steps

  • To verify the fix, run a manual test backup using the VSS snapshot method during a low-traffic window and monitor the SQL Server Error Log for Error 3087 recurrence—confirm the session IDs in the freeze and thaw messages now match.
  • If the error persists despite patching, temporarily switch the backup job to a native SQL Server backup (non-VSS) method as a workaround while engaging the backup vendor’s support team to investigate their VSS requestor session handling.