TL;DR
Install Postgres 9.6, and then:
sudo pg_dropcluster 9.6 main --stop
sudo pg_upgradecluster 9.5 main
sudo pg_dropcluster 9.5 main
Specifically for using the WAL-E enabled Docker image, make sure WAL-E is turned off:
sudo pkill backupcron
Install PostgreSQL:
sudo echo 'deb http://apt.postgresql.org/pub/repos/apt/ xenial-pgdg main' > /etc/apt/sources.list.d/pgdg.list
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | \
sudo apt-key add -
sudo apt update
sudo apt install postgresql-9.6 postgresql-client-9.6 postgresql-contrib-9.6
Use dpkg -l | grep postgresql
to check which versions of postgres are installed:
i postgresql - object-relational SQL database (supported version)
i A postgresql-9.5 - object-relational SQL database, version 9.5 server
i A postgresql-9.6 - object-relational SQL database, version 9.6 server
i A postgresql-client-9.5 - front-end programs for PostgreSQL 9.5
i A postgresql-client-9.6 - front-end programs for PostgreSQL 9.6
i A postgresql-contrib-9.5 - additional facilities for PostgreSQL
i A postgresql-contrib-9.6 - additional facilities for PostgreSQL
Run pg_lsclusters
, your 9.5 and 9.6 main clusters should be "online".
pg_lsclusters
Ver Cluster Port Status Owner Data directory Log file
9.5 main 5432 online postgres /var/lib/postgresql/9.3/main /var/log/postgresql/postgresql-9.5-main.log
9.6 main 5433 online postgres /var/lib/postgresql/9.5/main /var/log/postgresql/postgresql-9.6-main.log
There already is a cluster "main" for 9.6 (since this is created by default on package installation).
This is done so that a fresh installation works out of the box without the need to create a cluster first,
but of course it clashes when you try to upgrade 9.5/main when 9.6/main also exists.
The recommended procedure is to remove the 9.6 cluster with pg_dropcluster
and then upgrade with pg_upgradecluster
.
Stop the 9.6 cluster and drop it.
sudo pg_dropcluster 9.6 main --stop
Stop and Upgrade the 9.5 cluster to the latest version.
sudo service postgresql stop
sudo pg_upgradecluster 9.5 main
Note that the upgrade can take a long time for large databases. Eg a 15GB database can take hours (from personal experience). In this case you might want to run the pg_upgrade command manually with the -k -j8
switches. -k
creates symlinks to the original database and works directly on that, rather than copying it over. SO THIS IS A DESTRUCTIVE OPERATION - ONLY DO IF YOU HAVE BACKUPS. The -j
switch specifies how many CPU cores to use in the upgrade. Use 8 if you have an 8-core CPU.
sudo service postgresql stop
sudo -H -u postgres /usr/lib/postgresql/9.6/bin/pg_upgrade \
-b /usr/lib/postgresql/9.5/bin \
-B /usr/lib/postgresql/9.6/bin \
-d /var/lib/postgresql/9.5/main \
-D /var/lib/postgresql/9.6/main \
-o ' -c config_file=/etc/postgresql/9.5/main/postgresql.conf' \
-O ' -c config_file=/etc/postgresql/9.6/main/postgresql.conf' \
-k -j8
Your 9.5 cluster should now be "down".
pg_lsclusters
Ver Cluster Port Status Owner Data directory Log file
9.5 main 5433 down postgres /var/lib/postgresql/9.5/main /var/log/postgresql/postgresql-9.5-main.log
9.6 main 5432 down postgres /var/lib/postgresql/9.6/main /var/log/postgresql/postgresql-9.6-main.log
Check that the upgraded cluster works, then remove the 9.5 cluster.
sudo service postgresql start
sudo pg_dropcluster 9.5 main
If seeing file permission errors upon startup:
* The PostgreSQL server failed to start. Please check the log output:
2017-03-14 04:06:51 UTC FATAL: private key file "/var/lib/postgresql/ssl/ssl-cert-snakeoil.key" has group or world access
2017-03-14 04:06:51 UTC DETAIL: File must have permissions u=rw (0600) or less if owned by the database user, or permissions u=rw,g=r (0640) or less if owned by root.
2017-03-14 04:06:51 UTC LOG: database system is shut down
...fail!
Then simply fix the permissions:
sudo chmod 600 /var/lib/postgresql/ssl/*.key
If using WAL-E, push a new base backup:
sudo -u postgres envdir /etc/wal-e.d/env wal-e backup-push
Lastly update config (if required):
sudo vi /etc/postgresql/9.6/main/postgresql.conf
Change cluster_name = '9.5/main'
to cluster_name = '9.6/main'
.