Re: pg_upgrade fails if vacuum_defer_cleanup_age > 0

On Wed, Jun 10, 2020 at 04:07:05PM +0200, Laurenz Albe wrote:
> A customer's upgrade failed, and it took me a while to
> figure out that the problem was that they had set
> "vacuum_defer_cleanup_age=10000" on the new cluster.
> 
> The consequence was that the "vacuumdb --freeze" that
> takes place before copying commit log files failed to
> freeze "pg_database".
> That caused later updates to the table to fail with
> "Could not open file "pg_xact/0000": No such file or directory."
> 
> I think it would increase the robustness of pg_upgrade to
> force "vacuum_defer_cleanup_age" to 0 on the new cluster.

Wow, I can see setting "vacuum_defer_cleanup_age" to a non-zero value as
causing big problems for pg_upgrade, and being hard to diagnose.  I will
apply this patch to all branches.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee