Knowledge Base

Warning 170: "Log files are not in sequence" - on log shipping (restore) operation

Category: Troubleshooting & error messages
Date: 06 Jul 2011
Product: SQL Backup
You may see the following sequence of messages in the SQL backup logfile

6/9/2011 4:51:07 PM: Warning 170: Log files are not in sequence: '20110609_143000.sqb' and '20110609_155000.sqb'

6/9/2011 4:51:23 PM: SQL error 3013: SQL error 3013: RESTORE LOG is terminating abnormally.

6/9/2011 4:51:23 PM: SQL error 4326: SQL error 4326: The log in this backup set terminates at LSN 180210000000271700001, which is too early to apply to the database. A more recent log backup that includes LSN 180220000000211000001 can be restored.

SQL Server demands the log restores be done in the correct sequence.

What commonly happens is that there is a large log backup that takes a long time to copy, allowing newer (smaller) log files to make it to the log shipping share before the earlier (larger) one. This problem eventually sorts itself out over time, but if not you could change the log restore job to use a wider interval that is at least the transfer time of the largest backup.

There are also occasions where the log backup doesn't have a header. This can happen if SQL Backup could not retrieve the LSN numbers from the msdb database in a reasonable time. The solution to this problem is to manually restore the headerless log backup and then allow the log shipping restore job to continue.