Error YYYY/MM/DD hh:mm Expect log sequence 'abc' but found 'SERVERNAME\Microsoft Information Store\First Storage Group\E000def.log
Exchange is really sensitive when it comes to transaction logs. There are several potential causes for this error (in order below from most common to least)
- The previous Exchange backup job was interrupted while in progress. During subsequent backups, Exchange will expect a certain log sequence number (which never successfully uploaded to the backup software server), and backup software (or any backup software) will expect a different log sequence number... hence the error message.
- This error could occur when the log sequence of MS Exchange was altered by other backup software, e.g. NTBackup, BackupExec. Thus when backup software next performs a MS Exchange backup, the Exchange log sequence would not match the one that it is expecting. With the broken sequence, the Exchange server cannot be restored to its latest state.
- This error could also occur, if the user has changed the minimum size for In-file delta to a value smaller than the corresponding Exchange log file size, i.e. 1MB for MS Exchange 2007 and 5MB for MS Exchange 2000/2003. backup software would then generate deltas for Transaction log backups, thus causing the expected log sequence error.
To resolve this problem, you need to deactivate all other backup software that is operating on MS Exchange (if applicable), and then you need to perform a Full MS Exchange database backup manually via backup software.
See: Manual backup of Exchange, MS SQL, and MySQL
Alternatively, instead of backing up transaction logs during the weekdays, you can consider doing Full Exchange Database backup on a daily basis with the In-File Delta option enabled. This should avoid interference from other backup software while keeping the amount of upload data to minimal.
If the problem stems from the minimum size setting of In-file delta, you need to modify setting according to the MS Exchange database in concern.