EFI installation error

Trying to install latest tumbleweed alongside windows 10. First install grub was messed up so no graphical boot menu. I attempted re-install, I shrank the windows partition and added / home and swap but keep getting no efi partion, system may not boot. What am I doing wrong?

We cannot see what you are seeing.

If Windows is booting successfully, and if it is using UEFI, then there should already be an EFI partition. You should be able to check this.

The installer wants an EFI partition of at least 256M, and complains if it is smaller than that. However, if you have an EFI partition, and you think it is large enough, then just ignore the complaint and press on regardless. You might need to go into the expert partitioner, and tell it to mount the existing EFI partition at “/boot/efi”.

Note that Leap 15.0 uses the same partitioner as Tumbleweed. In my first install of 15.0 (then at Alpha level), it proposed an EFI partition of 33M. I went along with that. Some time later, it started complaining that the EFI partition needed to be at least 256M. I continued my install with the existing 33M partition, and all was fine. I did later redo that, to its new default of 512M.

Thanks. I didn’t want to ignore the error since the last install didn’t work. There is an EFI partition and I did mount it. I am still able to boot windows through the BIOS. For some reason the install does not write to the EFI partition. I will go again and ignore the error to see what happens. Do I need to specify EFI at install or should the installer sort that?

When you click on the partition (perhaps “/dev/sda1”) in the left column of the expert partitioner, there should be an edit button. When you click that, it should show more details about the partition. In particular, it should list it as an EFI partition.

If that all looks right, then check the box for “Mount partition”, and set it to mount at “/boot/efi”.

That should be enough for it to be recognized as the system EFI partition and to have booting done that way.

I’ll note that this assume you have booted the installer in EFI mode.

I made some blog posts about installing Leap 15.0:

Perhaps they might be helpful.

Yes, first time it wasn’t efi so maybe that was the problem. I’ll have a look at byour links and then have another go. Thanks for your help.

Thanks nrickert all sorted now. Posting this from my new install of tumbleweed and showing windows option at boot. I think what happened was this. For some reason i had two efi partitions, one 500 mb and the other 100. I had mounted the 500, which later vi found was empty. This install i mounted the 100mb and everything worked OK. Just wondering where the 500mb came from and if I can delete it?

If nothing in it you can delete it. Installer complains if size is less then 250 meg but can be ignored unless you have a ton of OS’s installed. Perhaps you created the new one in response to warning.

You can have multiple partitions but is not needed.

So presumably as all is working OK 100meg is fine, I don’t need to increase size?

Yes. Just ignore the installer complaints.

A little background. The UEFI specs say to use FAT, which could include FAT12, FAT16 and FAT32. But apparently they imply that only FAT32 should be used on the hard drive. And according to the Yast maintainers, 256M is the smallest partition size for FAT32.

Unless you have an unusually fussy BIOS, it will work just fine with a 100M EFI partition.

Excellent! Thanks very much for all your help. It’s easier to try stuff when you have someone who knows what they are doing. Thanks again.

Yes, quoting spec:

EFI encompasses the use of FAT32 for a system partition, and FAT12 or FAT16 for removable media.

In practice I do not remember any report about EFI firmware being unable to read other FAT implementations (would be rather silly anyway).

And according to the Yast maintainers, 256M is the smallest partition size for FAT32.

I am able to create FAT32 starting with size slightly less than 33MiB; do you have pointers to this statement?

Yes, that’s my experience. And I agree that it would be silly.

I am able to create FAT32 starting with size slightly less than 33MiB; do you have pointers to this statement?

I think it is somewhere in the bugzilla discussion. I’ll see if I can find it.

I read the same from ArchWiki.
Maybe one will say that is not the best source but for me it is enough - I never find a mistake.