I thought amazon converted them automatically? - Matt M (inactive)

Sadly no, and it cost me a month to find out. I'm writing a blog post about it. - Jorge Escobar

Doh.. That's what I would have assumed. We've got a whole set of X-large instances we need to convert, I was hoping it would "just work". Thanks for pointing this out. :) - Matt M (inactive)

@Matt the reserved instances need to be of the same type (i.e. m1-small) AND the same availabilty zone (us-1d, for example) - Jorge Escobar

Jorge - if those match, does Amazon automatically switch you over to the reserved billing? - Matt M (inactive)

Yes, they check hourly to see any matches - Jorge Escobar from IM

One thing was strange... I did a snapshot of my EBS and created a new one with this snapshot. However, when I attached it to the new reserved instance, it didn't pick the new data in MySQL for hours. I was hitting myself on the wall for not doing a MySQL dump before doing this. But today I checked, and all the data is there. SO weird... - Jorge Escobar