Not necessarily. While that could happen if there was a roughly even split of the hash power, if one side of the fork has more than the other e.g. 75% vs. 25%, then that scenario is no likely to happen. The fork with the greater hash power will extend their chain to become longer than the fork with less hash power. Since their blockchain would be longer, it is considered valid over the other blockchain. However, for not upgraded nodes, that longer chain would be invalid since it would contain blocks larger than 1 Mb.
but then the flip side is that the whole second doomsday scenario lauda and ciyam suggest, which is that bigger blocks take longer to process.
(yep im using
their own disaster theories against them)
and so the smaller miners would by default produce more blocks and so they would gain the blockheight, just by having less data to validate.
2mb miners would need to be ALOT more powerful than 1mb to gain the lead if there was not consensus
so as you said its all about the consensus and hashing power. and not a simple "2mb are evil doomsday".
Furthermore, depending on the forking mechanism, this may not be possible at all. If they use the forking mechanism which invalidates older versioned blocks (as is used now with soft forks), then any blocks produced by the old miners will be invalid because their version numbers are too old. If checkpointing is also used, then this scenario is not possible since one fork would have a history that the other fork does not. Due to the checkpoints, the upgraded miners would not be able to go back to the other fork which is what you are saying would happen.
exactly only in a change to the 'forking mechanism'(your words) to ignore older clients. and where the new 2mb miners have sufficiently more hash power to get ahead of the other miners with less processing time... and enough of the community of nodes not orphaning it. would we see the 2mb blocks win..
so as i said its not a doomsday event as soon as 2mb blocks hit the network. it requires extra things to occur, some nefarious some involving dominance in hashing power and some involving enough node acceptance..
otherwise miners are just wasting more than 10 minutes making blocks that get orphaned if they basically dont get consensus or have enough power to stay ahead of the other miners every time.
i do see exchanges halting their service because orphans can make so called 1confirmed transactions suddenly become unconfirmed again. so they wont want to risk it.. or atleast raise the threshold to a higher number of confirmations before crediting customers with funds.
(sidenote: which is another reason not to trust 0 confirms or 1 confirms if your buying a porsche or a house. the risk of that exact block being an orphan today is about 2%(3 orphans a day(144 blocks) at the moment) the risk of orphans during a blocksize battle could be as much as
)
and lastly.. i think that if we ignore the nefarious miner doomsday scenario's..
and stick with logic and greed, miners wont be making 1.005mb blocks until they know consensus has been reached, to protect their revenues from becoming unspendable. .. which is another factor to take into account that its not a doomsday scenario. but more like paranoid hypothesis of nefarious factors all colluding into one targetted agenda