apt error doesn’t support architecture ‘i386’

On an Ubuntu server, when running “apt update” command, I got the following error message

root@s196379:~# apt update
Hit:1 http://mirror.fcix.net/ubuntu focal InRelease
Hit:2 http://mirror.fcix.net/ubuntu focal-updates InRelease                
Hit:3 http://security.ubuntu.com/ubuntu focal-security InRelease           
Hit:4 https://mirror.rackspace.com/mariadb/repo/10.5/ubuntu focal InRelease
Reading package lists... Done
Building dependency tree       
Reading state information... Done
All packages are up to date.
N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'https://mirror.rackspace.com/mariadb/repo/10.5/ubuntu focal InRelease' doesn't support architecture 'i386'
root@s196379:~# 

This error is because the repository do not support i386. To fix the error, edit the file

vi /etc/apt/sources.list

Find

deb https://mirror.rackspace.com/mariadb/repo/10.5/ubuntu focal main

Replace with

Find

deb [arch=amd64] https://mirror.rackspace.com/mariadb/repo/10.5/ubuntu focal main

Solution 2: Remove i386 support

Check your architecture

dpkg --print-architecture 

If you are using 64 bit OS, you will see amd64.

Check if multiarch is enabled

dpkg --print-foreign-architectures

If you get “i386”, you have multiarch enabled.

If you don’t have any i386 applications running, you can remove i386 support with

dpkg --remove-architecture i386

If you want to enable i386 support, you can run

dpkg --add-architecture i386

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