# dnf update
...
Package glusterfs-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-libs-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-server-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-fuse-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-devel-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-api-devel-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-api-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-cli-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-client-xlators-5.4-1.fc28.x86_64.rpm is not signed
Package glusterfs-extra-xlators-5.4-1.fc28.x86_64.rpm is not signed
Package python3-gluster-5.4-1.fc28.x86_64.rpm is not signed
The downloaded packages were saved in cache until the next successful transaction.
You can remove cached packages by executing 'dnf clean packages'.
Error: GPG check FAILED

This is a development laptop and I never installed or need glusterfs-server.
I could remove glusterfs-server, but other glusterfs packages seems to be
required by libvirt, libguestfs and qemu.

I tried "dnf clean all" and removed yum/dnf caches, but it does not help.

In the meantime I could update by excluding glusterfs. I hope someone has a better
solution.

Nir