Any command I put into the LXTerminal of my raspberry pi, it says Sudo unable to resolve host (none) I can’t download anything, even Sudo apt-get update How do I fix this"?
The problem manifests itself when a command is issued under
sudo. For example:
$ sudo apt autoremove sudo: unable to resolve host the_name: Name or service not known Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
In other words, the command executes as it should, but the annoying error message appears after each use of
sudo: unable to resolve host <XXXX>: Name or service not known
I don't know what causes this issue, but here's something that may fix it:
- get your hostname from /etc/hostname, or:
$ cat /etc/hostname the_name # --OR-- $ hostname the_name
- check your
/etc/hostsfile; you may see something like this:
cat /etc/hosts 127.0.0.1 localhost 127.0.1.1 raspberrypi ::1 localhost ip6-localhost ip6-loopback ff02::1 ip6-allnodes ff02::2 ip6-allrouters
- There should be two entries for the loopback address (127.0.0.1). The problem is caused when one of the loopback addresses does not have the proper hostname assigned, or has no name assigned, or there is only one line for this address.
Remedy this by opening the
/etc/hosts file in your editor, and changing the hostname for second entry/line 127.0.0.1 to the same name that is in the
/etc/hostname file. Using this case as an example, change the second line:
You can double-check this after your edit - you should see this:
cat /etc/hosts 127.0.0.1 localhost 127.0.1.1 the_name ::1 localhost ip6-localhost ip6-loopback ff02::1 ip6-allnodes ff02::2 ip6-allrouters
And that should take care of it.