Why backup database by Barman can't reach end(pending)?

Question

Did operations:

barman cron
barman receive-wal --create-slot pg
barman receive-wal pg
barman switch-wal --force --archive pg

Then run check and backup command:

-bash-4.2$ barman check pg
Server pg:
    PostgreSQL: OK
    is_superuser: OK
    PostgreSQL streaming: OK
    wal_level: OK
    replication slot: OK
    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: OK
    pg_basebackup supports tablespaces mapping: OK
    systemid coherence: OK (no system Id stored on disk)
    pg_receivexlog: OK
    pg_receivexlog compatible: OK
    receive-wal running: OK
    archive_mode: OK
    archive_command: OK
    archiver errors: OK
-bash-4.2$ barman backup pg
Starting backup using postgres method for server pg in /var/lib/barman/pg/base/20200305T124531
Backup start at LSN: 0/5100A7B8 (000000010000000000000051, 0000A7B8)
Starting backup copy via pg_basebackup for 20200305T124531
(pending)

It can't finish after a very long time. Checked /var/lib/barman/pg/base/20200305T124531/ path:

• backup.info
• data

In data, it seems the data from pg server already been copied. See the content in backup.info:

backup_label=None
begin_offset=42936
begin_time=2020-03-05 12:45:31.020705+09:00
begin_wal=000000010000000000000051
begin_xlog=0/5100A7B8
config_file=/var/lib/pgsql/10/data/postgresql.conf
copy_stats=None
deduplicated_size=None
end_offset=None
end_time=None
end_wal=None
end_xlog=None
error=None
hba_file=/var/lib/pgsql/10/data/pg_hba.conf
ident_file=/var/lib/pgsql/10/data/pg_ident.conf
included_files=None
mode=postgres
pgdata=/var/lib/pgsql/10/data
server_name=pg
size=None
status=STARTED
systemid=6795775088862271947
tablespaces=None
timeline=1
version=100012
xlog_segment_size=16777216

Check process, got:

barman    5661  0.0  0.2 258560 19204 ?        Ss   12:45   0:00 /usr/bin/python2 /bin/barman -c /etc/barman.conf -q receive-wal pg
barman    5671  0.0  0.0 176384  3416 ?        S    12:45   0:00 /usr/pgsql-10/bin/pg_receivewal --dbname=dbname=replication host=pg options=-cdatestyle=iso replication=true user=streaming_barman application_name=barman_receive_wal --verbose --no-loop --no-password --directory=/var/lib/barman/pg/streaming --slot=barman
postgres  5675  0.0  0.0 397052  3844 ?        Ss   12:45   0:00 postgres: wal sender process streaming_barman 127.0.0.1(41570) streaming 0/534365C8
barman    5745  0.0  0.2 258564 19080 pts/0    S+   12:45   0:00 /usr/bin/python2 /bin/barman backup pg
barman    5751  0.0  0.0 176132  3316 pts/0    S+   12:45   0:00 /bin/pg_basebackup --dbname=dbname=replication host=pg options=-cdatestyle=iso replication=true user=streaming_barman application_name=barman_streaming_backup -v --no-password --pgdata=/var/lib/barman/pg/base/20200305T124531/data --no-slot --wal-method=none
postgres  5752  0.0  0.0 396724  7980 ?        Ss   12:45   0:00 postgres: wal sender process streaming_barman 127.0.0.1(41618) sending backup "pg_basebackup base backup"

Why it can't finish? status=STARTED Didn't update to finish status.

Answer 1

The reason was I did recovery after the first backup operation. Then Barman set a string #BARMAN# ahead archive_command = 'barman-wal-archive backup pg %p' command into the postgresql.conf file!

So it can't call that command when do the second backup.

Remove the string, it works.

The design to aim to don't allow user to use archive_command again after recovery?