Merci pour le post!
Je suis allé sur vos traces et j'ai corrigé le problème chez NAS ds112j!
Mon erreur après la restauration de 6.2 à 5.1 (s /var/log/messages): "DiskStation downloadman.cgi: downloadman.cpp:800 Failed to add task with selected BT files"
Supprimé "Download Station" supprimé DB via la console. D'abord, juste au cas où, j'ai fait une sauvegarde. Installé "Download Station", tout a fonctionné.
>ssh root@diskstation
DiskStation>cd /volume1/public/
DiskStation>mkdir /volume1/public/pgsql_bak/
DiskStation>cd /volume1/public/pgsql_bak/
DiskStation>pg_dump download > database_download_20-01-2023.sql
DiskStation>su postgres
/volume1/@database/pgsql $ psql
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-------------+--------------+-----------+---------+-------+-----------------------
download | postgres | SQL_ASCII | C | C |
mediaserver | MediaIndex | SQL_ASCII | C | C |
photo | PhotoStation | SQL_ASCII | C | C |
postgres | postgres | SQL_ASCII | C | C |
synolog | 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
postgres=#drop database download;
postgres=#\q
/volume1/@database/pgsql $exit
DiskStation> exit