problem with flushInterval in cacheModel

[Odelya Glick]

HI,

I have declared the following cacheModel
<cacheModel id="countriesCache" type="LRU">
                <flushInterval hours="720" />
                <property name="size" value="100" />
        </cacheModel>

But I get an exception that flush must be declared either with hours, min or
so.
When I changed it to hours="24" it's fine.

What's the limit? 

and if I want it to be cached for good?

(I don't think to ever change the countries table).

Thank you, 

Odelya 
web-programmer
050-2052075