How to fix Error 4339 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 4339 – RESTORE Statement Partial Completion

Why This Error Happens

Error 4339 occurs when a RESTORE statement completes some of its internal operations but cannot finish the entire sequence, typically due to corrupted backup media, an incomplete restore sequence (missing differential or log backups), or the restore process being interrupted before all data pages could be verified. This often happens when the backup file itself contains inconsistent or partially written data, or when the WITH RECOVERY option is applied prematurely before all required backup files in the restore chain have been applied. In some cases, insufficient disk space or abrupt termination of the SQL Server service during a long-running restore can also leave the database in this partially restored state.

Step-by-Step Resolution Guide

Step 1: Verify the Integrity of the Backup File

  • Run RESTORE VERIFYONLY FROM DISK = 'C:\Backups\YourBackup.bak' to confirm the backup file is not corrupted.
  • Check the file size and compare it against the original backup job logs to rule out truncation during file transfer.
  • If the backup resides on a network share, re-copy it locally to C:\SQLBackups\ to eliminate I/O or latency-related corruption.

Step 2: Confirm the Complete Restore Sequence is Applied

  • Ensure the full backup is restored first using WITH NORECOVERY, not WITH RECOVERY.
  • Apply any differential backups in order, also using WITH NORECOVERY.
  • Apply all transaction log backups sequentially, finishing the final log restore with WITH RECOVERY only on the last file.
  • Example command structure:
  RESTORE DATABASE YourDB FROM DISK = 'Full.bak' WITH NORECOVERY;
  RESTORE LOG YourDB FROM DISK = 'Log1.trn' WITH NORECOVERY;
  RESTORE LOG YourDB FROM DISK = 'Log2.trn' WITH RECOVERY;

Step 3: Check Disk Space and File Permissions

  • Confirm the target drive (e.g., D:\SQLData\) has sufficient free space for both the .mdf and .ldf files being restored.
  • Verify that the SQL Server service account has Full Control permissions on the destination folder via Windows Security settings.
  • Check Windows Event Viewer under Applications and Services Logs > MSSQLSERVER for any disk I/O or access-denied errors coinciding with the restore attempt.

Step 4: Restart the Restore with Error Checking Enabled

  • Use RESTORE DATABASE YourDB ... WITH CHECKSUM, STOP_AT_MARK to force SQL Server to validate each page during the restore.
  • If using SQL Server Management Studio (SSMS), enable Verify Backup Media in the restore dialog under the Options tab before executing.
  • Monitor the restore progress via sys.dm_exec_requests to catch any early termination signals.

Alternative or Verification Steps

  • After completing the restore sequence, run DBCC CHECKDB('YourDB') WITH NO_INFOMSGS, ALL_ERRORMSGS to confirm the database is structurally sound and fully recovered.
  • If Error 4339 persists, take a fresh full backup from the source server (ensuring no concurrent write operations occur during the backup) and retry the entire restore chain on the Windows Server 2025 target.