How to fix Error 3249 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 3249

Why This Error Happens

This error occurs when SQL Server detects that the media presented for a restore operation is not the first volume in a multi-volume backup set. It typically happens when backup files from a striped or multi-file backup set are provided out of sequence, or when a backup file is mistakenly treated as a standalone file when it is actually a continuation volume. Corrupted media headers or incorrectly concatenated backup files can also trigger this error, as SQL Server reads volume sequence metadata embedded in the backup header to validate order.

Step-by-Step Resolution Guide

Step 1: Identify All Volumes in the Backup Set

  • Locate every file or tape associated with the original backup operation (e.g., BackupFile1.bak, BackupFile2.bak, BackupFile3.bak).
  • Check the original backup script or job history in SQL Server Agent to confirm how many files/devices were used in the BACKUP DATABASE statement.
  • Use RESTORE LABELONLY FROM DISK = 'C:\Backups\BackupFile1.bak' to inspect media labels and sequence numbers.

Step 2: Reconstruct the Correct Restore Command

  • Ensure the restore statement lists all volumes in the exact order they were created, starting with the first volume.
  • Example syntax:
RESTORE DATABASE [YourDB]
FROM DISK = 'C:\Backups\BackupFile1.bak',
     DISK = 'C:\Backups\BackupFile2.bak',
     DISK = 'C:\Backups\BackupFile3.bak'
WITH RECOVERY;
  • Do not attempt to restore using only the second or third file in the set — SQL Server requires the starting volume to initialize the restore header.

Step 3: Validate File Integrity and Permissions

  • Confirm the SQL Server service account has read access to the folder, typically C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Backup\.
  • Check that none of the .bak files were truncated, renamed, or corrupted during transfer (e.g., FTP in ASCII mode instead of Binary mode).
  • Run RESTORE VERIFYONLY FROM DISK = 'C:\Backups\BackupFile1.bak' to confirm the first volume is valid and readable.

Step 4: Re-run the Backup if Files Are Unrecoverable

  • If the first volume is missing or corrupted beyond repair, the entire multi-volume set is unusable for restore.
  • Schedule a fresh full backup using BACKUP DATABASE with a single destination file (or properly labeled multiple files) to avoid future sequencing issues.

Alternative or Verification Steps

  • After restoring, run DBCC CHECKDB on the restored database to confirm consistency and that no data was lost during the fix.
  • If multiple volumes continue to cause ordering issues, consider switching future backups to a single backup file destination (or use a backup compression tool with built-in catalog tracking) to eliminate volume-sequence errors entirely.