How to fix Error 1122 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: Error 1122 – Page Alignment Failure in SQL Server 2025

Why This Error Happens

Error 1122 occurs when DBCC CHECKDB encounters a page structure where internal pointer addresses do not fall on proper byte-alignment boundaries, indicating physical corruption at the storage level. This is typically caused by faulty disk I/O subsystems, improper shutdowns, or storage drivers silently dropping writes (torn pages) before they reach the physical disk. In virtualized or SAN-backed environments running Windows Server 2025, this can also stem from misconfigured write-caching policies that violate SQL Server’s I/O guarantees.

Step-by-Step Resolution Guide

Step 1: Isolate the Database and Run Diagnostics

  • Place the affected database in single-user mode or take it offline for other connections to prevent further writes during diagnosis.
  • Run DBCC CHECKDB ('YourDatabaseName') WITH NO_INFOMSGS, ALL_ERRORMSGS, DATA_PURITY; to confirm the scope of corruption.
  • Note the specific PageID (%SPGID) referenced in the error log located at C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Log\ERRORLOG.

Step 2: Verify Hardware and Storage Integrity

  • Check the Windows Event Viewer under Windows Logs > System for Disk or NTFS warnings (Event ID 7 or 51) occurring around the same timestamp as the SQL error.
  • Run chkdsk C: /f /r (or the relevant drive letter hosting the .mdf/.ndf files) via an elevated Command Prompt to scan for and repair file system-level sector errors.
  • If using a SAN or virtual disk, verify that the storage controller cache is configured for “Write Through” rather than “Write Back” unless a Battery Backup Unit (BBU) is confirmed active.

Step 3: Restore from a Clean Backup

  • Since alignment errors usually indicate non-recoverable physical damage, the safest fix is restoring the specific database from the last known good backup.
  • Use RESTORE DATABASE [YourDatabaseName] FROM DISK = 'E:\Backups\LastGood.bak' WITH REPLACE, RECOVERY; to overwrite the corrupted file structure entirely.
  • Ensure the backup predates the first occurrence of the error in the logs to avoid restoring already-corrupted pages.

Step 4: Execute Repair as a Last Resort

  • If no valid backup exists, revert to single-user mode using ALTER DATABASE YourDatabaseName SET SINGLE_USER WITH ROLLBACK IMMEDIATE;.
  • Run DBCC CHECKDB ('YourDatabaseName', REPAIR_ALLOW_DATA_LOSS); to force SQL Server to deallocate the corrupted page.
  • Be aware this action will result in the permanent loss of data contained within that specific page.

Alternative or Verification Steps

  • Verify the Fix: Re-run DBCC CHECKDB immediately after the restore or repair process completes; a clean result with “0 allocation errors and 0 consistency errors” confirms the fix was successful.
  • Alternative Check: If the error persists immediately after a restore, run the Windows Memory Diagnostic Tool (mdsched.exe), as faulty RAM on the host server can sometimes cause SQL Server to write misaligned data to disk even when the storage hardware itself is healthy.