Follow this
Disk Space Management procedures for the Symantec Endpoint Protection Manager
http://www.symantec.com/business/support/index?page=content&id=TECH96214
You can do the following:
1. change the number of revisions retained by the Symantec Endpoint Protection Manager
2. edit the database retention settings for the Symantec Endpoint Protection Manager to help save disk space:
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Try the following links this should fix you're issue ....
Symantec Endpoint Security Manager: How is Database Maintenance scheduled?
http://www.symantec.com/business/support/index?page=content&id=TECH95880&locale=en_US
Changing the log settings to reduce the size of the database
http://www.symantec.com/business/support/index?page=content&id=TECH105238&locale=en_US
How to quickly purge the SEPM log tables on a SQL server
http://www.symantec.com/business/support/index?page=content&id=TECH132880&locale=en_US