Upgrading Postgres from 10 to 12 -- problem with encodings - postgresql

Question

I'm trying to upgrade a postgres server from 10 12, and am having problems with the encodings. I'm following what I believe to be established recipes.
Behold:
postgres#serverbot:~$ psql -l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-------------+----------+-----------+---------+-------+-----------------------
postgres | postgres | SQL_ASCII | C | C |
template0 | postgres | SQL_ASCII | C | C | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | SQL_ASCII | C | C | postgres=CTc/postgres+
| | | | | =c/postgres
thingsboard | postgres | SQL_ASCII | C | C | =Tc/postgres +
| | | | | postgres=CTc/postgres+
| | | | | nagios=c/postgres
(4 rows)
Notice the encodings on the 10 database. Time to create the database for 12.
postgres#serverbot:~$ sudo service postgresql stop
postgres#serverbot:~$ /usr/lib/postgresql/12/bin/initdb -E SQL_ASCII --locale=C -D /var/lib/postgresql/12/data
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.
The database cluster will be initialized with locale "C".
The default text search configuration will be set to "english".
Data page checksums are disabled.
creating directory /var/lib/postgresql/12/data ... ok
creating subdirectories ... ok
selecting dynamic shared memory implementation ... posix
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting default time zone ... America/New_York
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok
initdb: warning: enabling "trust" authentication for local connections
You can change this by editing pg_hba.conf or using the option -A, or
--auth-local and --auth-host, the next time you run initdb.
Success. You can now start the database server using:
/usr/lib/postgresql/12/bin/pg_ctl -D /var/lib/postgresql/12/data -l logfile start
Excellent! Let's fire up the new server.
postgres#serverbot:~$ /usr/lib/postgresql/12/bin/pg_ctl -D /var/lib/postgresql/12/data -l logfile start
waiting for server to start.... done
server started
And verify the encodings...
postgres#serverbot:~$ psql -l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+-----------+---------+-------+-----------------------
postgres | postgres | SQL_ASCII | C | C |
template0 | postgres | SQL_ASCII | C | C | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | SQL_ASCII | C | C | =c/postgres +
| | | | | postgres=CTc/postgres
(3 rows)
Everything matches... time to upgrade!
postgres#serverbot:~$ /usr/lib/postgresql/12/bin/pg_upgrade \
--old-datadir=/var/lib/postgresql/10/main \
--new-datadir=/var/lib/postgresql/12/main \
--old-bindir=/usr/lib/postgresql/10/bin \
--new-bindir=/usr/lib/postgresql/12/bin \
--old-options '-c config_file=/etc/postgresql/10/main/postgresql.conf' \
--new-options '-c config_file=/etc/postgresql/12/main/postgresql.conf' \
--link --check
Performing Consistency Checks
-----------------------------
Checking cluster versions ok
Checking database user is the install user ok
Checking database connection settings ok
Checking for prepared transactions ok
Checking for reg* data types in user tables ok
Checking for contrib/isn with bigint-passing mismatch ok
Checking for tables WITH OIDS ok
Checking for invalid "sql_identifier" user columns ok
encodings for database "postgres" do not match: old "SQL_ASCII", new "UTF8"
Failure, exiting
postgres#serverbot:~$
Doh!
What is wrong here? I assert that the encodings do match, and I'm stuck.
Can anyone offer any advice?

Answer 1

What I see is:
postgres#serverbot:~$ /usr/lib/postgresql/12/bin/pg_ctl -D /var/lib/postgresql/12/data -l logfile start
waiting for server to start.... done
server started
and then:
postgres#serverbot:~$ /usr/lib/postgresql/12/bin/pg_upgrade \
--old-datadir=/var/lib/postgresql/10/main \
--new-datadir=/var/lib/postgresql/12/main \
[...]
Note the $PGDATA directories. The database cluster you did the initdb for is different from the one you are doing the pg_upgrade to.
UPDATE. Since you seem to be using a Debian based OS and it's Postgres packaging, it might work better to stick with the packaging tools:
sudo pg_createcluster --locale=C 12 ascii
Creating new PostgreSQL cluster 12/ascii ...
/usr/lib/postgresql/12/bin/initdb -D /var/lib/postgresql/12/ascii --auth-local peer --auth-host md5 --locale C
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.
The database cluster will be initialized with locale "C".
The default database encoding has accordingly been set to "SQL_ASCII".
The default text search configuration will be set to "english".
Data page checksums are disabled.
fixing permissions on existing directory /var/lib/postgresql/12/ascii ... ok
creating subdirectories ... ok
selecting dynamic shared memory implementation ... posix
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting default time zone ... America/Los_Angeles
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok
Success. You can now start the database server using:
pg_ctlcluster 12 ascii start
Ver Cluster Port Status Owner Data directory Log file
12 ascii 5434 down postgres /var/lib/postgresql/12/ascii /var/log/postgresql/postgresql-12-ascii.log
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+-----------+---------+-------+-----------------------
postgres | postgres | SQL_ASCII | C | C |
template0 | postgres | SQL_ASCII | C | C | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | SQL_ASCII | C | C | =c/postgres +
| | | | | postgres=CTc/postgres
(3 rows)
Also I would use pg_upgradecluster, see here for more information. This keeps everything in the same system.