Re: pg_rewind copy so much data

On Wed, Sep 13, 2017 at 2:21 PM, Hung Phan <hungphan227(at)gmail(dot)com> wrote:
> If I run pg_rewind with debug option, it just show additional bunch of files
> copied in directories like base or pg_tblspc. I claim that there is no data
> inserted of modified from the first step. The only difference between two
> server is caused by restarting old master.

That's exactly this kind of data that would allow to conclude where
the data comes from, and you are not showing it, so it is not possible
to make a clear conclusion. Are known the file paths, the offset
position in the file where a chunk of data is taken, and the chunk
size. If you see for example a bunch of 8kB blocks being copied, this
means that some extra load ran on the master before it was stopped,
and before running the rewind. Are you sure that you don't have large
log files for example?

I would be curious to know what is the version of Postgres 9.5 you are
using as well.
--
Michael