macOS Big Sur was already released. However, many people reported that they got Installation failed error.
See this: What to Do If Your macOS Big Sur Installation Failed/Stuck/Frozen/Slow

normally sebab internet tak cukup kuat

Always backup with time machine before installing new os update

mine jz stucked in loading for 30 mins... normal?

yesterday morning their servers were having issues, by lunch time it was fine, managed to update my Mac mini server and the other Macs just pulls Big Sur image directly from the mini without a problem

loading as in? boot screen? if boot screen, use another device to ssh into the device to issue reboot command. one of my Mac was stuck at the boot screen for quite some time, which it was doing nothing in the background. Reboot and the installation completes just fine

I experienced that many times, just have to keep trying!

I got the fail installation issue yesterday and today. Gave up, will try again later next week.

Just installed. No issues at all. It black screen for a while when on 27 minutes left , rebooted itself twice and again on 9 minutes left but after that everything okay.