From server End
Login Console
Go to Policies Tab then "Antivirus and Antispyware policy".
open the "Antivirus and Antispyware policy" policy
Go to Miscelleanous Tab and Go Log Handling.
There Antivirus and Antispyware log Event Filtering tab available, there you can able to check that content which you need to required in log entry
other option is "Log Retention" where the log time period mention, only mention day log will be avail on client systems. You can able to change it as per you required.
From Client end
Open the client Shield.
In the Shield there is option Tab avail under "Antivirus and Antispyware policy".
Select the option Tab and choose "change setting".
There is General Tab where log setting avail, you can able to change it from there as well.