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Nonce size - Will it always be big enough?
My question may be misphrased, if so, I'll correct it if you let me know in the comments.
My understanding of mining is that the header is appended with some nonce
and that is SHA256'd to get some hash, let's say: 7050a40746c695a220acb99c725ef66b29aa863707b17ba939c8bb1f5ec52b67
This happens until there are X number of consecutive 0's in that hash. Is there a guarantee that there will always be at least X 0's in a row for every block header?