Document Type | Troubleshooting
Category | Administration
Applicable Product Versions | 6FS01, 6FS02, 6FS03, 6FS04, 6FS05, 6FS06, 6FS07, 6FS07PS, 7FS01, 7FS02, 7FS02PS
Document Number | TADTS037
Issue
As part of security vulnerability measures, some systems may change the access permissions of the /etc/hosts file. This can cause Tibero to fail to start.
Tibero checks the localhost address information through the /etc/hosts file during startup, and if this information is missing, startup may fail. By default, it is in a world-readable state.
Checking the status of /etc/hosts and /etc/resolv.conf - default permission is 644.
[root@centro1 /]# cd /etc [root@centro1 etc]# ls -la|grep hosts -rw-r--r--. 1 root root 158 Apr 24 04:04 hosts [root@centro1 etc]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 [root@centro1 etc]# cat /etc/resolv.conf -Generated by NetworkManager nameserver 168.126.63.1 nameserver 8.8.8.8
This is a case where the /etc/nsswitch.conf file has been modified to intentionally prevent resolving the IP corresponding to localhost.
#hosts: files dns myhostname hosts: files dns This hosts entry in the /etc/nsswitch.conf file defines the hostname lookup order on Linux or Unix-based systems. The meaning of each entry is as follows: files โ refer to the /etc/hosts file first dns โ resolve names via DNS server myhostname โ use the local hostname (like /etc/hostname) as a final fallback Removing myhostname causes the NSS module to fail to map the hostname. [root@centro1 etc]# chmod -x /etc/hosts [root@centro1 etc]# ls -la|grep hosts -rw-r--r--. 1 root root 158 Apr 24 04:04 hosts [root@centro1 etc]# chmod 400 hosts [root@centro1 etc]# ls -la|grep hosts -r--------. 1 root root 158 Apr 24 04:04 hosts [root@centro1 etc]# ping localhost PING localhost(localhost (::1)) 56 data bytes 64 bytes from localhost (::1): icmp_seq=1 ttl=64 time=0.109 ms 64 bytes from localhost (::1): icmp_seq=2 ttl=64 time=0.076 ms ^C --- localhost ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1032ms rtt min/avg/max/mdev = 0.076/0.092/0.109/0.019 ms [root@centro1 etc]# su - tibero Last login: Fri May 2 04:24:03 EDT 2025 on pts/0 [tibero@centro1 ~]$ ping localhost ping: localhost: Name or service not known [tibero@centro1 ~]$ tbboot Change core dump dir to /home/tibero/tibero7/bin/prof. Listener port = 8629 ERROR: Cannot convert the address localhost. Tibero instance startup failed!
Cause
Tibero needs to verify the IP corresponding to localhost during startup, but if all resolution paths are blocked, it cannot obtain this information and thus fails to start.
Solutions
It is possible to start Tibero by configuring it to resolve the IP corresponding to localhost through methods other than the /etc/hosts file. You can enable DNS lookup, NSS modules, or other resolution paths.