Hi Bruce, On 6/14/19 5:30 AM, Bruce Momjian wrote: >> Also, I do not think it best practice (or perhaps not correct at all) to >> use '--size-only' > > --size-only is correct, as far as I know. > Maybe I am missing something, but I am of the opinion that --size-only should not be used when syncing database content (and probably in many other use cases where content can change over time). The reason is that db allocates blocks, 8K by default regardless from the content. Using --size-only, tells rsync to only check the size of the blocks. That is: if the block is present on the destination, and is the same size as the origin, then skip. I understand that in this thread we are contextualizing in a step by step procedure to create a new standby, but I have anyway a few remarks about it (and the documentation where it has been copied from) and I would be glad if you or somebody else could shed some light on it. *) It might happen in some corner cases that when syncing the standby, rsync dies and the DBA does not realize it. It will then start the master and some data gets modified. At the time the DBA realizes the issue on the standby, he will stop master and resume the sync. Changes happened on the master will then not be propagated to the standby if they happened on files already present on the standby. *) It might be a long shot because I do not have time now to reproduce the situation of the standby at that exact point in time, but I think that --size-only option is there probably to speed up operations. In that case I do not see a reason for it since the data folder on the standby is assumed to be empty regards, fabio pardi
