Need a glossary for Postgres backup terminology

[dulhaver]

Summary

Glossary of items returned by a barman check [server] report

Rationale

getting started with barman seems extremly tedious endeavour. One thing which is missing terribly is to understand what errors mean, or what they even refer to.

In example and barman check [server] report can show quite some FATAL errors and it's quite tricky to even figure out what those problems referr to.

here is real-life example:

:~> barman check pg
Server pg:
        WAL archive: FAILED (please make sure WAL shipping is setup)
        PostgreSQL: FAILED
        directories: OK
        retention policy settings: OK
        backup maximum age: OK (no last_backup_maximum_age provided)
        compression settings: OK
        failed backups: OK (there are 0 failed backups)
        minimum redundancy requirements: OK (have 0 backups, expected at least 0)
        pg_basebackup: OK
        pg_basebackup compatible: FAILED (PostgreSQL version: None, pg_basebackup version: 12.6)
        systemid coherence: OK (no system Id available)
        pg_receivexlog: OK
        pg_receivexlog compatible: FAILED (PostgreSQL version: None, pg_receivexlog version: 12.6)
        receive-wal running: FAILED (See the Barman log file for more details)
        archiver errors: OK

so, the non-expert user would have no clou what an item (i.e. WAL archive, pg_basebackup compatible or receive_was running) which may have FAILED refers to. You can't even tell whether someting is a problem on the barman backup sercer or the postgresql server.

Due to that you don't have any handle to even start troubleshooting which can be a quick show-stopper and likewise a great loss for the user (not able to use barman) and the community (less members/users)

[josh-heyer]

See also #2090

[josh-heyer]

Await: homepage reorg / category pages