How to solve the LSN mismatch issue in alwayson mirror SQL server The mirror database has insufficient transaction log data to preserve the log backup chain of the principal database. This may happen if a log backup from the principal database has not been taken or has not been restored on the mirror database

  There are many times, we face the LSN mismatch issue in alwaysON and other HA technologies. It is a bit hard to find the missing transaction log backup to apply. Since, there are hundreds of thousands log generated, depends on the transaction log frequency and it can be run in any secondary alwaysON database server. Think about “the VLDB” and “the backup is in different data center” and database are out of sync in DR site because of LSN mismatch. For VLDB 8 TB database, we cannot take a full or differential backup to fix this. Since, it will take more and more time. Backup is in different data center…