Processed 701 pages for database

Hi All,

I am getting the below error, 

BACKUP LOG OPCSA TO DISK = ''

Processed 701 pages for database 'OPCSA', file 'sparcsn4_log' on file 1.
The log was not truncated because records at the beginning of the log are pending replication or Change Data Capture. Ensure the Log Reader Agent or capture job is running or use sp_repldone to mark transactions as distributed or captured.
BACKUP LOG successfully processed 701 pages in 0.093 seconds (58.845 MB/sec).

Thank you,

JP