Is this business rent or residential rent? If it is residential then the PRTB applies, if it is business then I'm not so sure.
Anyway, if it is residential then he can only raise it to the market rate. Also the notice period increases with time, 30 days for first year, 45 days for second year (or something like that). If you have been there 30 years I would say you have a substantial notice period saved up (assuming the law applies to rents prior to 2004).
again check out PRTB.ie for more details.