setting -i and -N 100 when starting postmaster

Hi all,

My wonderful colleagues in charge of our production database have screwed up royally. They managed to corrupt the
productiondatabase by having two instances of postgresql talking  
to the same database/same filesystem/same time. Now, they'd like me to fix it. Sigh...

BTW, this is a V9.2.2 system, and the database will still start, but the logs are full of reports pf invalid page
headererrors. One thing I'm looking at is doing a "ps -ef | grep  
postmaster", I see "service postgresql-9.2 start" uses:

postmaster -D /opt/datacenter -i -N 384 -p 5431

Now, I know what the -D and -p are doing, but I'm not sure what -i and -N are for, and my internet search hasn't turned
upmuch. Anybody know? 
--
Jay

PS. Any suggestions beyond setting zero_damaged_pages=true and then running a vacuum would also be appreciated.