有備無患

Preparedness averts peril. / to be prepared, just in case (idiom)

to have; there is / (bound form) having; with; -ful; -ed; -al (as in 有意[you3 yi4] intentional)

to suffer (from illness) / to contract (a disease) / misfortune / trouble / danger / worry

not to have / no / none / not / to lack / un- / -less

to prepare / get ready / to provide or equip

(bound form) to prepare; to equip / (literary) fully; in every possible way