Symptoms
Assume that you are using Microsoft SQL Server Always-On availability groups (AG). When you take a transaction log backup on the asynchronous secondary replica, you may encounter a backup failure with an error message that resembles the following:
Backup detected log corruption in database xx. Context is FirstSector. LogFile: x x:\xx_log.ldf' VLF SeqNo: xx VLFBase: xx LogBlockOffset: xx SectorStatus: xx LogBlock.StartLsn.SeqNo: xx LogBlock.StartLsn.Blk: xx Size: xx PrevSize: xx
If you retry a couple of times, the log backup may complete successfully.
Resolution
Cumulative Update Information for SQL Server:
This issue is fixed in the following cumulative update for SQL Server:
Cumulative Update 7 for SQL Server 2016 RTM
Cumulative Update 4 for SQL Server 2016 SP1
Cumulative Update 6 for SQL Server 2014 SP2
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Latest cumulative update for SQL Server 2016
Service Pack Information for SQL Server 2012:
This issue is fixed in the following service pack for SQL Server:
Service Pack 4 for SQL Server 2012
For more information about how to obtain the latest service pack, see How to obtain the latest service pack for SQL Server 2012
Service packs are cumulative. Each new service pack contains all the fixes that are in previous service packs, together with any new fixes. Our recommendation is to apply the latest service pack and the latest cumulative update for that service pack. You do not have to install a previous service pack before you install the latest service pack. Use Table 1 in the following article for finding more information about the latest service pack and latest cumulative update.
How to determine the version, edition and update level of SQL Server and its components
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminologythat Microsoft uses to describe software updates.