pg_dump of database with numerous objects

I have always used pg_basebackup to backup my database and I have never
had any issues.

I am now needing to upgrade to a new version of PostgreSQL and I am
running into problems when pg_upgrade calls pg_dump. pg_dump stalled at:
"pg_dump: saving database definition" for 24 hours before I killed the
process.

My pg_class table contains 9,000,000 entries and I have 9004 schema.

I was able to get output from pg_dump if I used the -n option to dump
schema with wildcards. I was able to use -n 'data???x' where x was a
digit from 0 to 9. This way I was able to execute 10 concurrent pg_dump
processes and dump the database in 30 minutes. I then dumped the public
schema and used pg_dumpall to dump the globals.

Can anyone tell me if there is something else I need to do to manually
dump the database? What I did do seems to have restored correctly on the
upgraded server, but if I want to make sure that I haven't missed
anything that will creep up on me.