How to fix Error 10656 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: Error 10656 – Resumable Index Operation Paused

Why This Error Happens

Error 10656 occurs when SQL Server automatically pauses a resumable index creation or rebuild operation, typically due to a failover, lock timeout, user-initiated pause, or loss of connection to the database engine during the operation. This behavior is by design in SQL Server’s resumable index feature, but it can also be triggered by insufficient transaction log space, memory pressure, or an unexpected session termination. In some cases, underlying disk I/O issues or corrupted index metadata on Windows Server 2025 can prevent the operation from completing normally, forcing SQL Server to pause it as a safety mechanism.

Step-by-Step Resolution Guide

Step 1: Verify the Current State of the Paused Index Operation

  • Run the following query to check index operation status:
  SELECT * FROM sys.index_resumable_operations;
  • Confirm the state_desc column shows PAUSED and note the percent_complete value.
  • Check SQL Server Error Log via SSMS or C:\Program Files\Microsoft SQL Server\MSSQL16.MSSQLSERVER\MSSQL\Log\ERRORLOG for related entries.

Step 2: Check System Resources and Transaction Log Space

  • Open Task Manager or Performance Monitor on Windows Server 2025/Windows 11 to check for memory and CPU pressure.
  • Verify transaction log free space:
  DBCC SQLPERF(LOGSPACE);
  • If log space is low, expand the log file via SSMS: Right-click database → Properties → Files → increase file size or enable autogrowth.
  • Ensure the drive hosting .ldf files has sufficient free disk space (recommended minimum 20% free).

Step 3: Resume the Index Operation

  • Execute the resume command once resources are confirmed stable:
  ALTER INDEX [YourIndexName] ON [YourSchema].[YourTable] RESUME;
  • If the operation fails again immediately, abort and restart cleanly:
  ALTER INDEX [YourIndexName] ON [YourSchema].[YourTable] ABORT;
  • Rebuild using the resumable option explicitly:
  ALTER INDEX [YourIndexName] ON [YourSchema].[YourTable] REBUILD WITH (ONLINE = ON, RESUMABLE = ON, MAX_DURATION = 60 MINUTES);

Step 4: Check for Failover or Connectivity Interruptions

  • If using an Always On Availability Group, confirm there were no recent failovers in Failover Cluster Manager on Windows Server 2025.
  • Review the Windows Event Viewer (Applications and Services Logs > MSSQLSERVER) for connectivity drops correlating with the pause timestamp.
  • Stabilize network connectivity between the client/application server and the SQL Server instance before retrying.

Alternative or Verification Steps

  • After resuming, re-run SELECT * FROM sys.index_resumable_operations; and confirm percent_complete reaches 100 and the row disappears upon completion.
  • If the issue persists, drop the resumable operation entirely with ALTER INDEX ... ABORT, then recreate the index using CREATE INDEX ... WITH (ONLINE = ON) as a non-resumable fallback.