Comment 0 for bug 1919261

In a host where ceph-mds is installed, upgrading from 14.2.11-0ubuntu0.19.10.1~cloud4 to 15.2.8-0ubuntu0.20.04.1~cloud0 fails with:

dpkg: error processing archive /tmp/apt-dpkg-install-Zen6uw/9-ceph-common_15.2.8-0ubuntu0.20.04.1~cloud0_amd64.deb (--unpack):
 trying to overwrite '/usr/bin/cephfs-data-scan', which is also in package ceph-mds 14.2.11-0ubuntu0.19.10.1~cloud4
dpkg-deb: error: paste subprocess was killed by signal (Broken pipe)
Errors were encountered while processing:
 /tmp/apt-dpkg-install-Zen6uw/9-ceph-common_15.2.8-0ubuntu0.20.04.1~cloud0_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

The problem happens because /usr/bin/cephfs-data-scan is provided by ceph-mds in 14.2.11-0ubuntu0.19.10.1~cloud4:

# dpkg -S /usr/bin/cephfs-data-scan
ceph-mds: /usr/bin/cephfs-data-scan

However in 15.2.8-0ubuntu0.20.04.1~cloud0 it is provided by ceph-common:

# dpkg -S /usr/bin/cephfs-data-scan
ceph-common: /usr/bin/cephfs-data-scan

A quick workaround is to temporarily remove ceph-mds before the upgrade (dpkg -r ceph-mds) and then perform the upgrade process using apt install. It will upgrade all packages and reinstall ceph-mds.