brain-dump/android/updating-hosts-file.md

Updating the Hosts File on Android

:warning: Magisk has a warning for A/B slot devices not to modify /system with regards to OTA; if you don't want to re-flash Magisk after every update, check out these alternatives for hosts files:

• Built-in toggle for systemless hosts in Magisk app
• DNS66

Using a rooted Android device with non-A/B slots

Pre-requisites:

• Rooted phone
• ADB
• Updated hosts file

1. Plug a USB in and mount the phone to a computer running ADB.

2. In a terminal, run:

   adb root
   

   to access the device with root permissions.

3. Copy the local hosts file from your desktop (for example) onto the device:

   adb push /home/angela/Desktop/hosts /system/etc/hosts
   

   [100%] /system/etc/hosts

Check your /system/etc/ or /etc directory and you should see the hosts file modified time with today's date.

Troubleshooting

Unable to mount read-only filesystem.

Simply run:

adb remount
adb root

Usually fixes the read-write issue.