While executing pg_start_backup function I am getting below warning
test=# select pg_start_backup(to_char(now(), 'yyyy-mm-dd hh24:mi:ss'));
WARNING: could not read symbolic link "pg_tblspc/oth_data_tbs": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/str_index": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/tbs_temp_default": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/oth_indx_tbs": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/str_data_ids": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/tbs_default": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/top_indx_tbs": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/rpt_data_tbs": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/str_data_h_index": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/rpt_indx_tbs": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/str_data": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/str_data_h": Invalid argument
WARNING: could not read symbolic link "pg_tblspc/top_data_tbs": Invalid argument
pg_start_backup
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5/E0000028
(1 row)