Ubuntu Server更新时出现es.archive.ubuntu.com解析失败DNS问题求助

Hey there, I’ve dealt with this exact DNS issue a few times on Ubuntu servers without resolvconf, so let’s walk through the fixes step by step.

First: Verify Your /etc/network/interfaces Config #

First off, double-check that your DNS settings are correctly added in /etc/network/interfaces. You should have a dns-nameservers line under your network interface block, like this:

Example valid config snippet:

auto eth0
iface eth0 inet static
    address 192.168.1.100
    netmask 255.255.255.0
    gateway 192.168.1.1
    dns-nameservers 8.8.8.8 8.8.4.4  # Google Public DNS servers

If this line is missing or has invalid DNS addresses, add correct ones first.

Step 1: Temporary DNS Fix (Test If It Works) #

Since you don’t have resolvconf, Ubuntu won’t automatically populate /etc/resolv.conf from your interfaces file. Let’s manually set it up to test:

• Back up your empty resolv.conf first:

  sudo cp /etc/resolv.conf /etc/resolv.conf.bak
  

• Edit the file with a text editor:

  sudo nano /etc/resolv.conf
  

• Add these lines (use any reliable DNS servers you prefer):

  nameserver 8.8.8.8
  nameserver 8.8.4.4
  

• Save and exit (Ctrl+O, Enter, then Ctrl+X in nano).
• Test if resolution works:

  ping es.archive.ubuntu.com
  

If you get responses, the DNS issue is resolved temporarily. Now let’s make this permanent.

Step 2: Permanent Fix (Prevent resolv.conf From Being Overwritten) #

Ubuntu might use tools like systemd-resolved that overwrite /etc/resolv.conf automatically. Here’s how to lock in your static DNS:

1. Check if systemd-resolved is running:

   systemctl status systemd-resolved
   

2. If it’s active, disable and stop it:

   sudo systemctl disable --now systemd-resolved
   

3. If /etc/resolv.conf is a symbolic link (common with systemd-resolved), remove it:

   sudo rm /etc/resolv.conf
   

4. Recreate the static resolv.conf file with your DNS servers (same as step 1):

   sudo nano /etc/resolv.conf
   

5. Make the file immutable so no service can overwrite it:

   sudo chattr +i /etc/resolv.conf
   

Step 3: Reload Network Settings #

Finally, restart your network service to ensure all changes take effect:

sudo systemctl restart networking
# Or for older Ubuntu versions:
# sudo /etc/init.d/networking restart

Test the update command again:

sudo apt update

It should now resolve the repository URL without errors.

内容的提问来源于stack exchange，提问作者Yus