Comment # 16 on bug 1220276 from Ancor Gonzalez Sosa

A couple of remarks, just for completeness.

1) This behavior is not Agama-specific. YaST does the same.

2) In the past, YaST tried to share the existing EFI in the system, even if it
was not in the system in which (open)SUSE was being installed. At some point we
decided to change that and create a new EFI partition in the target disk. That
was advised by Raymund Will. See
https://github.com/yast/yast-storage-ng/pull/877 and other links there.

Some of the relevant content for (2) is at a Trello card. So let's me paste it
here (with the poor formatting capabilities of Bugzilla):

> What SLE-15-GA and SLE-15-SP1 do?
> ---------------------------------
> 
> When reusing an existing ESP, we prefer to use a partition
> in the root_disk. But if there is none there, we also accept
> reusing an ESP partition from another disk.
> 
> Is that right?
> --------------
> 
> I (Ancor) am not sure. The current implementation assumes
> (or seems to assume) that an EFI-compliant firmware will look
> for the ESP partition in any disk. So even with a multi-disk
> setup, there should be just one ESP in the system shared by
> all the operating systems, no matter in which disk(s) each
> operating system actually resides. But I'm not sure whether
> that is actually true or whether the real expectation should
> be that every disk should contain its own ESP shared only by
> the operating systems that reside in that particular disk.
> 
> What to do for SP2?
> -------------------
> 
> Steffen Winterfeld discussed this with Raymund Will and they
> agreed that ESP should only be reused if it is in the disk
> used for installation. That applies also to other boot-related
> partitions like bios_boot, PReP and Zipl. That is, never use
> any other disk.