How to fix Error 4315 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 4315 – “Some Files Still Require More Restore Steps”

Why This Error Happens

Error 4315 occurs when an online restore sequence is incomplete because the database contains filegroups or files that have not yet had all required differential or transaction log backups applied. This typically happens when a RESTORE DATABASE…WITH RECOVERY statement is issued prematurely, before every file marked as “restoring” has received its full chain of backups. It can also occur if a filegroup was taken offline mid-sequence and the backup chain for that specific file was broken or skipped.

Step-by-Step Resolution Guide

Step 1: Verify the Current Restore State of All Files

  • Open SQL Server Management Studio (SSMS) and connect to the instance via a new query window.
  • Run the following query to identify files still pending restoration:
SELECT name, physical_name, state_desc 
FROM sys.master_files 
WHERE database_id = DB_ID('YourDatabaseName');
  • Look specifically for a state_desc value of RESTORING, which confirms the file has not completed its sequence.

Step 2: Apply the Missing Backup Files in the Correct Order

  • Locate the specific differential or log backup files in your backup directory (e.g., C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Backup\).
  • Execute the restore command using the WITH NORECOVERY clause to keep the database in a loading state until the sequence is fully complete:
RESTORE LOG YourDatabaseName 
FROM DISK = 'C:\Backup\YourDatabase_Log1.trn' 
WITH NORECOVERY;
  • Repeat this process sequentially for every log or differential backup taken after the initial full backup.

Step 3: Finalize the Restore Sequence

  • Once all files show a consistent recovery LSN (Log Sequence Number) and no pending files remain, issue the final recovery command.
  • Run the command without specifying a backup file to bring the database online:
RESTORE DATABASE YourDatabaseName WITH RECOVERY;
  • Check the SQL Server Error Log (via SSMS or C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Log\ERRORLOG) to confirm the recovery process finished without further warnings.

Step 4: Check for File-Specific Corruption or Permissions Issues

  • If Step 2 fails repeatedly for a specific file, verify the SQL Server service account (e.g., NT Service\MSSQLSERVER) has Read/Write permissions on the backup folder.
  • Navigate to the folder properties via File Explorer, select the Security tab, and ensure the service account is not restricted.

Alternative or Verification Steps

  • Verification: Run RESTORE HEADERONLY FROM DISK = 'path_to_backup_file' to confirm the BackupStartDate and BackupFinishDate align sequentially with no gaps in the LSN chain.
  • Alternative: If a specific log backup file is corrupted and cannot be applied, you may need to restore the database using WITH RECOVERY at the last known good restore point, accepting potential data loss for transactions occurring after that specific backup.