@Milfont, The Hangzhou2 protocol changes the structure of the Tezos context, flattening certain nested indexes. The result optimizes storage use, but it requires to translate the whole context storage between schemas – the migration in the quoted phrase. This will happen automatically during the activation of Hangzhou, after the last block of the Granada protocol, which still uses the current schema, and before the first block of Hangzhou2 – which will use the new schema.
This will be, again, an automated process, that requires no input from the user.
However, it will take some time: from 20 – 30 minutes for rolling and full nodes to 2 – 3 hours for archive nodes.
The procedure in this post (for rolling/full nodes) aims at reducing this slowdown by making sure the context storage is as lean as possible, by importing a fresh snapshot close the end of cycle 427.
There is more information available:
- in this recent announcement published in Marigold’s blog; and
- in this Agora discussion.
