Configuring a DNS Server for Domain Name Resolution

A DNS server is used to resolve domain names of general-purpose file systems. For details about DNS server IP addresses, see What Are Huawei Cloud Private DNS Server Addresses?

Scenarios

By default, the IP address of the DNS server is automatically configured on ECSs when ECSs are created. No manual configuration is needed except when the resolution fails due to a change in the DNS server IP address.

Procedure (Linux)

Log in the ECS as user root.
Run vi /etc/resolv.conf to edit the /etc/resolv.conf file. Add the DNS server IP address above the existing nameserver information.

Figure 1 Configuring DNS
The format is as follows:
```
nameserver 100.125.1.250
```
Press Esc, enter :wq, and press Enter to save and exit.
Check whether the IP address is successfully added.

cat /etc/resolv.conf
Check whether the domain name of the general-purpose file system can be resolved.

nslookup <domain-name-of-the-general-purpose-file-system>

Obtain the domain name of a general-purpose file system from its mount point. For example, if the mount point of a general-purpose file system is xxx:/sfs-name-001, xxx is the file system domain name, and sfs-name-001 is the file system name.
(Optional) If DHCP is configured for the ECS, edit the /etc/resolv.conf file to prevent the file from being automatically modified upon an ECS startup, and prevent the DNS server IP address added in 2 from being reset.
1. Lock the file.
  chattr +i /etc/resolv.conf
  
  Run chattr -i /etc/resolv.conf to unlock the file if needed.
2. Check whether the file is locked.
  lsattr /etc/resolv.conf
  
  If the information shown in Figure 2 is displayed, the file is locked.
  
  Figure 2 File locked