For it to disappear from steemd is quite something.
Steemd.com is also a front end. As far as I know, there are API nodes owned by witnesses who are not Sun's puppets. Removing the post from the chain itself would require a hard fork. Or would it? It would if all the hashes of the previous blocks included in the blocks were all recalculated and checked against the existing ones to ensure the integrity of the chain at regular intervals. Otherwise any witness could calmly remove or alter transactions in old blocks without raising alarm. When a new block is added to Steem, is the entire chain of hashes recalculated to check the integrity of the chain?
Do you know where I can find my old post if not on Steemd?
It's still there, because I can access it via the comment that remains (one other comment disappeared along with the post)
Hmmm...you can try the eSteem desktop or mobile apps. They talk to the API nodes directly.