Retain BODS job logs longer

Hi Guys,

I want to keep BODS job logs for more than 30days. (BODS web administrator -> status) I referred to online help and changed the settings in BODS. But, I still don't understand the difference between "history" and "job server log" retention. Can anyone help to explain it? Thanks

https://help.sap.com/viewer/e54136ab6a4a43e6a370265bf0a2d744/4.2.11/en-US/571aace66d6d1014b3fc9283b0e91070.html