问题描述：

在使用“物理备份+WAL日志备份”的时候，执行pg_stop_backup()时候发生错误：

postgres=# select pg_stop_backup();
NOTICE:  pg_stop_backup cleanup done,waiting for required WAL segments to be archived
WARNING:  pg_stop_backup still waiting for all required WAL segments to be archived (60 seconds elapsed)
HINT:  Check that your archive_command is executing properly.  pg_stop_backup can be canceled safely,but the database backup will not be usable without all the WAL segments.
WARNING:  pg_stop_backup still waiting for all required WAL segments to be archived (120 seconds elapsed)
HINT:  Check that your archive_command is executing properly.  pg_stop_backup can be canceled safely,but the database backup will not be usable without all the WAL segments.
WARNING:  pg_stop_backup still waiting for all required WAL segments to be archived (240 seconds elapsed)
HINT:  Check that your archive_command is executing properly.  pg_stop_backup can be canceled safely,but the database backup will not be usable without all the WAL segments.

此时我的 archive_command的配置是：

rchive_command = 'cp %p /home/postgres/archive/%f'

前几次操作的时候会跳出来这些信息，网上查找其他的资料说警告信息可以直接忽略，但是在此次操作中没有成功。