Migrating to a Different Server
If the need arises ownCloud can be migrated to a different server. A typical
use case would be a hardware change or a migration from the virtual Appliance
to a physical server. All migrations have to be performed with ownCloud
offline and no accesses being made. Online migration is supported by
ownCloud only when implementing industry standard clustering and HA solutions
before ownCloud is installed for the first time.
To start let us be specific about the use case. A configured ownCloud
instance runs reliably on one machine. For some reason (e.g. more powerful
machine is available but a move to a clustered environment not yet needed)
the instance needs to be moved to a new machine. Depending on the size of
the ownCloud instance the migration might take several hours. As a
prerequisite it is assumed that the end users reach the ownCloud instance
via a virtual hostname (a CNAME record in DNS) which can be pointed at
the new location. It is also assumed that the authentication method
(e.g. LDAP) remains the same after the migration.
Note
At NO TIME any changes to the ORIGINAL system are required
EXCEPT putting ownCloud into maintenance mode.
This ensures, should anything unforseen happen you can go
back to your existing installation and provide your users
with a running ownCloud while debugging the problem.
- Set up the new machine with the desired OS, install and configure the
Web server as well as PHP for ownCloud (e.g. permissions or file upload size
limits) and make sure the PHP version matches ownCloud supported
configuration and all relevant PHP extensions are installed. Also set up
the database and make sure it is an ownCloud supported configuration. If
your original machine was installed recently just copying that base
configuration is a safe best practice.
- On the original machine then stop ownCloud. First activate the
maintenance mode. After waiting for 6-7 minutes for all sync clients to
register the server as in maintenance mode stop the application and/or
Web server that serves ownCloud.
- Create a dump from the database and copy it to the new machine. There
import it in the database (See Backing up ownCloud and Restoring ownCloud).
- Copy all files from your ownCloud instance, the ownCloud program files, the
data files, the log files and the configuration files, to the new
machine (See Backing up ownCloud and Restoring ownCloud). The data files should keep
their original timestamp (can be done by using rsync with -t option)
otherwise the clients will re-download all the files after the migration.
Depending on the original installation method and the OS the files are
located in different locations. On the new system make sure to pick the
appropriate locations. If you change any paths, make sure to adopt the paths
in the ownCloud config.php file. Note: This step might take several hours,
depending on your installation.
- While still having ownCloud in maintenance mode (confirm!) and BEFORE
changing the CNAME record in the DNS start up the database, Web server /
application server on the new machine and point your web browser to the
migrated ownCloud instance. Confirm that you see the maintenance mode
notice, that a logfile entry is written by both the Web server and
ownCloud and that no error messages occur. Then take ownCloud out of
maintenance mode and repeat. Log in as admin and confirm normal function
of ownCloud.
- Change the CNAME entry in the DNS to point your users to the new
location.