Resolution of ora-21561

Using SQL plus to connect Oracle database on Linux

[root@china ~]# sqlplus test/test@ORCL

SQL*Plus: Release 11.2.0.3.0 Production on Thu May 31 11:06:15 2018

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ERROR:
ORA-21561: OID generation failed

Solution process
input on the terminal: ~ host name
China
View/etc/hosts file: ~ cat/etc/hosts
127.0.0.1 localhost
keep the host name consistent with the name corresponding to 127.0.0.1 in hosts file

[root@china ~]# cat /etc/hosts
127.0.0.1   china
::1         localhost localhost.localdomain localhost6