When a Symantec Critical System Protection [SCSP] Agent is installed or moved to a new SCSP Manager, SCSP will start to read large Log files from the start of the file.
Article ID: 161026
Critical System Protection
Data Center Security Server
Critical System Protection Client Edition
Data Center Security Server Advanced
Installing a fresh agent or moving to a new Manager while monitoring a Large Log files via a "TextLog" Policy, causes the agent to read all event data from the start of the file.