Can’t see disk during Installation of macos Big Sur

Go back to the recovery main screen and enter Disk Utility.

From the View button, select Show all devices.

You should have an APFS container with at least one Volume.

If you have a drive in ExFAT, NTFS, MS-DOS, you’ll need to erase the drive. Use GUID Partition Map and APFS format. Name the volume whatever you’d like it to be.

What is showing is an External Drive

Actually your physical drive is missing which most likely means the physical drive has failed. The "Apple disk image Media" with "macOS Base System" is the virtual volume for the maOS installer. You will need to get the Mac repaired. I hope you have a backup since your data is most likely permanently gone now.

You should always have frequent and regular backups.

> As of writing now, the laptop is working fine. Any solution to this ?

I'd make backups to external disks (preferably one bootable with Carbon Copy Cloner) and sign out from iCloud and other services. Then try a clean Big Sur install from a bootable USB flash drive by formatting the whole internal device (not just the volumes) and check a few days if the problem recurs. If yes, replace the internal drive with a SSD (TLC, not QLC) and copy the CCC clone back to it (or make a clean install and restore from a backup).

Hey rashu1!

Good question! I would backup your Mac as soon as possible while you still can, as losing important data is not good.

Once done, you can feel confident in erasing the HD, and reinstalling a new copy of the OS, and/or taking it in for repair knowing your data is stored and safe.

Typically before bringing it in, etc. I’d follow this article:

What to do before you sell, give away, or trade in your Mac:

https://support.apple.com/en-us/HT201065

The big part of that, in my opinion is signing out of the Apple ID and other services, because you can erase your Mac, but if it’s locked to your iCloud account or other service, anyone, even repairers may not be able to fix it.

I think the number one thing is the data though, so just make sure you have some type of backup, before you can’t anymore:

Back up your Mac with Time Machine:

https://support.apple.com/en-us/HT201250

Archive or make copies of the information you store in iCloud:

https://support.apple.com/en-us/HT204055

Many times, erasing and reinstalling the OS fixes file system and other issues alone, however if it does need to be repaired, I’d cover all my bases

Hope that helps!

As noted by P. Phillips, your drive has failed.

macOS Base System is the disk image of the Recovery Volume.

If that is all you see, you don't have a functioning internal drive.