How can I go back from static IP to dynamic IP?

Question

In the past, I set a static IP to my Raspberry Pi 3. Now, I want to use it to other purpose and the subnet has changed. I don't remember how I set it to static. I have looked some questions but no one applies to my case. I have check "interfaces" and "dhcpcd.conf". Both are like they suppose to be. When I try to modify dhcpcd.conf I get "Error writing dhcpcd.conf: no space left on device".

Answer 1

Unless you solve the no space left on device, you will not be able to change anything.

The easiest way to get some space is to throw away logging. Under /var/log there are many logs (probably). Anything ending in gz is probably fine to delete (unless you want to review old logs; in that case: move it to an USB-stick). You may also move some other stuff to a USB-stick.

In your /etc/dhcpcd.conf, you probably have lines like this (with other IP addresses, possibly)

interface eth0
static ip_address=192.168.178.53/24
static routers=192.168.178.1
static domain_name_servers=192.168.178.56
interface wlan0
static ip_address=192.168.178.3/24
static routers=192.168.178.1
static domain_name_servers=192.168.178.56

Remove those lines (or make them comment).

And restart the dhcpcd:

systemctl restart dhcpcd.service

Or reboot.