Yup - did that. Here's the log from my abortive re-install:-
Removing existing packages
zimbra-ldap...done
zimbra-logger...done
zimbra-mta...done
zimbra-snmp...done
zimbra-store...done
zimbra-core...done
Removing deployed webapp directories
Installing packages
zimbra-core......zimbra-core_7.1.2_GA_3268.UBUNTU10_64_amd64.deb...
done
zimbra-ldap......zimbra-ldap_7.1.2_GA_3268.UBUNTU10_64_amd64.deb...done
zimbra-logger......zimbra-logger_7.1.2_GA_3268.UBUNTU10_64_amd64.deb...done
zimbra-mta......zimbra-mta_7.1.2_GA_3268.UBUNTU10_64_amd64.deb...
done
zimbra-snmp......zimbra-snmp_7.1.2_GA_3268.UBUNTU10_64_amd64.deb...done
zimbra-store......zimbra-store_7.1.2_GA_3268.UBUNTU10_64_amd64.deb...
done
Setting defaults from saved config in /opt/zimbra/.saveconfig/config.save
HOSTNAME=localhost
LDAPHOST=
LDAPPORT=
SNMPTRAPHOST=
SMTPSOURCE=
SMTPDEST=
SNMPNOTIFY=0
SMTPNOTIFY=0
LDAPROOTPW=zimbra
LDAPZIMBRAPW=zimbra
LDAPPOSTPW=zmpostfix
LDAPREPPW=zmreplica
LDAPAMAVISPW=zmamavis
LDAPNGINXPW=zmnginx
Restoring existing configuration file from /opt/zimbra/.saveconfig/localconfig.xml...done
Operations logged to /tmp/zmsetup.08222011-135148.log
Installing LDAP configuration database...done.
Upgrading from to 7.1.2_GA_3268
Stopping zimbra services...failed. exiting.
UPGRADE FAILED - exiting.
root@mail:/home/simon/zcs-7.1.2_GA_3268.UBUNTU10_64.20110804130819#
root@mail:/home/simon/zcs-7.1.2_GA_3268.UBUNTU10_64.20110804130819#
root@mail:/home/simon/zcs-7.1.2_GA_3268.UBUNTU10_64.20110804130819#
root@mail:/home/simon/zcs-7.1.2_GA_3268.UBUNTU10_64.20110804130819#
root@mail:/home/simon/zcs-7.1.2_GA_3268.UBUNTU10_64.20110804130819#
root@mail:/home/simon/zcs-7.1.2_GA_3268.UBUNTU10_64.20110804130819#
root@mail:/home/simon/zcs-7.1.2_GA_3268.UBUNTU10_64.20110804130819# cd /tmp
root@mail:/tmp# cat zmsetup.08222011-135148.log
Mon Aug 22 13:51:48 2011 Operations logged to /tmp/zmsetup.08222011-135148.log
Mon Aug 22 13:51:49 2011 Installing LDAP configuration database...
Mon Aug 22 13:51:49 2011 done.
Mon Aug 22 13:51:49 2011 *** Running as zimbra user: /opt/zimbra/libexec/zmldapschema 2>/dev/null
Looking for LDAP installation...succeeded
Installing core schema...
Installing cosine schema...
Installing inetOrgPerson schema...
Installing zimbra schema...
Installing amavis schema...
Installing dynlist schema...
Mon Aug 22 13:51:50 2011 Upgrading from to 7.1.2_GA_3268
Mon Aug 22 13:51:50 2011 Stopping zimbra services...
Mon Aug 22 13:51:50 2011 *** Running as zimbra user: /opt/zimbra/bin/zmcontrol stop
Host localhost
Stopping stats...Done.
Stopping mta...Done.
Stopping spell...Done.
Stopping snmp...Done.
Stopping cbpolicyd...Done.
Stopping archiving...Done.
Stopping antivirus...Done.
Stopping antispam...Done.
Stopping imapproxy...Done.
Stopping memcached...Done.
Stopping mailbox...Failed.
Stopping mailboxd...mailboxd is not running.
Error: assertion '-r /opt/zimbra/conf/my.cnf' failed
Stopping logger...Done.
Stopping zmconfigd...Done.
Stopping ldap...Done.
Mon Aug 22 13:51:58 2011 failed. exiting.
Mon Aug 22 13:51:58 2011 UPGRADE FAILED - exiting.
root@mail:/tmp#
I'm really not liking that it is setting hostname to 'localhost' - if I run hostname I get the FQDN, the resolv.conf tells it to use the local DNS which has the zone configured for my local machine. So I don't get why it is so unhappy?