Hi Carlos,
It says peer authentication failed for user “respaldo”. For this user, please check authentication type in pg_hba.conf file. For peer authentication, a mapping to OS user is needed and should be set in pg_ident.conf file.
For the working instance, is it the same authentication type?
If config files are updated already, may be a server restart(reload config files) didnt happen and the changes were not effective.
Please see the 4th use case here, we have mentioned an example of how peer authentication misconfiguration can cause issue for “postgres” user. Same is applicable here
https://documentation.commvault.com/2022e/expert/21723_backup_troubleshooting.html#cause-4
Regards,
Meera