Configuring DNS

A DNS server is used to resolve domain names of SFS Turbo file systems. For details about DNS server IP addresses, see What Are Private DNS Servers and What Are Their 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 to 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, as shown in Figure 1.

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

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

nslookup File system domain name

Obtain the file system domain name from the file system shared path.
(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 to 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