And here would be the output of apt-cache policy:
Package files:
100 /var/lib/dpkg/status
release a=now
500 http://download.gluster.org/pub/gluster/glusterfs/3.7/3.7.16/Debian/jessie/apt/
jessie/main amd64 Packages
origin download.gluster.org
500 http://ftp.ch.debian.org/debian/ jessie-updates/main Translation-en
500 http://ftp.ch.debian.org/debian/ jessie-updates/main amd64 Packages
release o=Debian,a=stable-updates,n=jessie-updates,l=Debian,c=main
origin ftp.ch.debian.org
500 http://security.debian.org/ jessie/updates/main Translation-en
500 http://security.debian.org/ jessie/updates/main amd64 Packages
release v=8,o=Debian,a=stable,n=jessie,l=Debian-Security,c=main
origin security.debian.org
Pinned packages: