[systemd-devel] systemd-repart MountPoint fails for esp partitions

[Karel Zak]

On Tue, Mar 25, 2025 at 09:00:09PM -0600, Thayne Harbaugh wrote:
> Response in-line:
> 
> On Tue, 2025-03-25 at 16:53 -0600, Thayne Harbaugh wrote:
> > Greetings,
> > 
> > systemd-repart MountPoint fails to generate a correct fstab entry for
> > esp partitions.  It generates a standard partition UUID which does
> > not
> > work for FAT file systems - a FAT volume ID must be used analogous to
> > what is generated for vfat in mkfs-util.c:make_filesystem().  The FAT
> > volume ID is in the form of 32 bits of uppercase hex digits with a
> > dash "-" between the high and low 16 bits: XXXX-XXXX (where X
> > represents an uppercase hex digit).
> > 
> > Attached is a patch I have been using with systemd v257 to provide
> > correct behavior.
> 
> Something did not like the .patch attachment - here it is in-line:
> 
> 
> 
> Use the PARTUUID to mount ESP partitions
> 
> The ESP vfat partition fails to mount because the UUID generated by repart
> matches neither the vfat serial number (although it's somewhat comparable) nor
> the partition UUID. 

I don't understand this. I thought that ESP is a partition on GPT and
all GPT partitions have UUIDs (aka PARTUUID). Why, in this case, do we
need to generate a UUID based on the filesystem? Do you want to
address the partition or filesystem in the fstab?

    Karel




-- 
 Karel Zak  <kzak at redhat.com>
 http://karelzak.blogspot.com