Debian9系统下如何为/etc/resolv.conf设置chattr +i属性？

Let's walk through the straightforward steps to make /etc/resolv.conf immutable using the chattr +i command, tailored to your Debian 9 setup:

Step 1: Check /etc/resolv.conf's file type #

First, confirm if /etc/resolv.conf is a regular file or a symbolic link (some network configurations use symlinks here):

ls -l /etc/resolv.conf

If it's a symlink, you'll need to apply the attribute to the target file instead of the symlink itself—chattr doesn't work on symlinks directly.

Step 2: Apply the immutable attribute #

Modifying file attributes requires root access, so run this command with sudo:

sudo chattr +i /etc/resolv.conf

This locks the file, preventing any user (including root) from modifying, deleting, or renaming it until you explicitly remove the attribute.

Step 3: Verify the attribute is active #

To confirm the immutable flag is set correctly, use:

lsattr /etc/resolv.conf

You should see an i in the output (e.g., ----i--------e--- /etc/resolv.conf), which indicates the file is immutable.

Key Notes to Remember #

• If you ever need to edit /etc/resolv.conf, you must first remove the immutable attribute:

  sudo chattr -i /etc/resolv.conf
  

  Make your changes, then re-run sudo chattr +i /etc/resolv.conf to lock it again.
• Your findmnt command returning no output is odd, but since Debian is installed on /dev/sda2 (almost certainly an ext4 filesystem, which supports the extended attributes required for chattr) and you have ACL installed, this shouldn't interfere with setting the immutable attribute. Just ensure you always use sudo for the chattr commands to avoid permission issues.

内容的提问来源于stack exchange，提问作者scrapy