I noticed this during beta1, but dismissed the issue when it wasn't easily reproducible. Now, I saw the same problem while upgrading from beta1 to beta2, so couldn't dismiss it. It turns out that LOs are lost if VACUUM FULL was run.
| /usr/pgsql-15b1/bin/initdb --no-sync -D pg15b1.dat -k | /usr/pgsql-15b1/bin/postgres -D pg15b1.dat -c logging_collector=no -p 5678 -k /tmp& | psql -h /tmp postgres -p 5678 -c '\lo_import /etc/shells' -c 'VACUUM FULL pg_largeobject' | rm -fr pg15b2.dat && /usr/pgsql-15b2/bin/initdb --no-sync -k -D pg15b2.dat && /usr/pgsql-15b2/bin/pg_upgrade -d pg15b1.dat -D pg15b2.dat -b /usr/pgsql-15b1/bin | /usr/pgsql-15b2/bin/postgres -D pg15b2.dat -c logging_collector=no -p 5678 -k /tmp& Or, for your convenience, with paths in tmp_install: | ./tmp_install/usr/local/pgsql/bin/initdb --no-sync -D pg15b1.dat -k | ./tmp_install/usr/local/pgsql/bin/postgres -D pg15b1.dat -c logging_collector=no -p 5678 -k /tmp& | psql -h /tmp postgres -p 5678 -c '\lo_import /etc/shells' -c 'VACUUM FULL pg_largeobject' | rm -fr pg15b2.dat && ./tmp_install/usr/local/pgsql/bin/initdb --no-sync -k -D pg15b2.dat && ./tmp_install/usr/local/pgsql/bin/pg_upgrade -d pg15b1.dat -D pg15b2.dat -b ./tmp_install/usr/local/pgsql/bin | ./tmp_install/usr/local/pgsql/bin/postgres -D pg15b2.dat -c logging_collector=no -p 5678 -k /tmp& postgres=# table pg_largeobject_metadata ; 16384 | 10 | postgres=# \lo_list 16384 | pryzbyj | postgres=# \lo_export 16384 /dev/stdout lo_export postgres=# table pg_largeobject; postgres=# \dt+ pg_largeobject pg_catalog | pg_largeobject | table | pryzbyj | permanent | heap | 0 bytes | I reproduced the problem at 9a974cbcba but not its parent commit. commit 9a974cbcba005256a19991203583a94b4f9a21a9 Author: Robert Haas <rh...@postgresql.org> Date: Mon Jan 17 13:32:44 2022 -0500 pg_upgrade: Preserve relfilenodes and tablespace OIDs. -- Justin