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.
This issue is fixed in the following cumulative update for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 4017080 - Last Review: Aug 8, 2017 - Revision: 12