Sorry, i know i am a little late for migration to nextcloud - especially from such an old owncloud instance.
Please be keen.
I tried to follow this post:
My system:
Debian 7
Mysql 5.5.40
Apache 2.22
Owncloud 8.2.1.4
(all installed via apt-get install owncloud)
(my config points to data dir: /vagrant/data/owncloud)
What i did:
cd /var/www
;#most up-to-date version in point of writing
wget https://download.nextcloud.com/server/releases/nextcloud-9.0.58.tar.bz2
tar xvjf nextcloud-9.0.58.tar.bz2
cp -R owncloud/config nextcloud/config
cp -R owncloud/data nextcloud/data
chown -R www-data /var/www/nextcloud
cd /var/www/nextcloud
su www-data
php occ maintenance:install
But this installs nextcloud using a sqlite database - empty, no users, no files. All data is missing.
There was no “update” command available in command line tool occ.
It is not absolute clear to me, if i need to update owncloud 8.2.14 to owncloud 8.2.11 (released on Apr 18 2017; most up-to-date version in point of writing) prior to migrating to nextcloud.
Yes, normally you should update to the latest 8.2.x release first. If you change the path of your data folder, you should have a look into your config/config.php and check the paths. The database should fix the paths to the data-folder but that has been implemented recently. I would first upgrade keeping the original locations (at least for the data folder). If then everything works, I would touch the data folder (and I would also use a rather recent version, NC 11, or in a few weeks NC 12).
For NC 9, you need at least php 5.6, Debian 7 has an older version by default.