Upgrade from PG12 to PG

Hello,

I want to upgrade from PG12 to P15.

I use /usr/lib/postgresql15/bin/pg_upgrade -v -p 5431 -P 5432

I takes a lot of time, more than 6 hours

Log file, al lot of  lines pg_restore: executing BLOB 1

Looking at the dump file: man many lines like SELECT
pg_catalog.lo_unlink('100000');

I have the same issue with /usr/lib/postgresql15/bin/pg_upgrade -v -p
5431 -P 5432 -k

Whats going on ?

Kind regards