Re: Upgrade master/slave: rsync?

Thinking more on this in my situation. The databases I've inherited have
the default system tables in the default tablespaces under $PGDATA
(/var/lib/pgsql/9.2/data), but then also has most of the app-specific data
on separate tablespaces outside of the data directory (eg various
directories under /opt/postgres). Of course this also means the various
symlinks to these from $PGDATA/pg_tblspc. For these, pg_upgrade will create
a new directory (PG_9.6_201608131) with hard-links (assuming I used the
--link option) to the old PG_9.2_201204301 directory, and then add symlinks
from the new 9.6 $PGDATA directory to the tablespace location.

I'm just trying to walk through this in my head. I'd need to run a similar
rsync command for each of these. For example, for tablespace foo with
location /opt/postgres/foo:

cd /opt/postgres/foo
rsync --archive --delete --hard-links --size-only PG_9.2_201204301
PG_9.6_201608131 standby.host.com:/opt/postgres/foo

And then rinse & repeat for any others similar tablespaces for each
standby/slave?

Another question. I have one slave in the same datacenter as the master,
the other slaves are in the DR data center across the country. I'm assuming
I could sync those DR slaves from the local slave? That way I can get the
master back online and serving requests as soon as the local slave is
successfully upgraded rather than waiting for rsync over the WAN? And then
one DR slave could be copied from the other so I only have to do the WAN
rsync once (especially if it's a downstream standby in a cascading
scenario)?

Don.

--
Don Seiler
www.seiler.us