The problem is the upgrade fails during the package installation from the Zimbra Repositories I get the following errors during upgrade:
I cannot recover from this error because any attempt to re-run the installation if you fix these issues, LDAP is not running because all packages get uninstalled, and during the installation of the new packages, the system breaks. My upgrade strategy now is to export all the mailboxes and then import them into a new system.Unpacking zimbra-spamassassin-rules (1.0.0-1zimbra8.7b1.14.04) ...
dpkg: error processing archive /var/cache/apt/archives/zimbra-spamassassin-rules_1.0.0-1zimbra8.7b1.14.04_all.deb (--unpack):
trying to overwrite '/opt/zimbra/data/spamassassin/rules/72_active.cf', which is also in package zimbra-mta 8.6.0.GA.1153.UBUNTU14.64
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
Unpacking zimbra-perl-mail-spamassassin (3.4.1-1zimbra8.7b1.14.04) ...
dpkg: error processing archive /var/cache/apt/archives/zimbra-perl-mail-spamassassin_3.4.1-1zimbra8.7b1.14.04_all.deb (--unpack):
trying to overwrite '/opt/zimbra/data/spamassassin/localrules/v340.pre', which is also in package zimbra-mta 8.6.0.GA.1153.UBUNTU14.64
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
Unpacking zimbra-osl (1.0.9-1zimbra8.7b1.14.04) ...
dpkg: error processing archive /var/cache/apt/archives/zimbra-osl_1.0.9-1zimbra8.7b1.14.04_all.deb (--unpack):
trying to overwrite '/opt/zimbra/docs/open_source_licenses.txt', which is also in package zimbra-core 8.6.0.GA.1153.UBUNTU14.64
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)