When checking out the setup for our OwnCloud system it came up with a few cautionary problems that needed to be resolved.

The problems related to environment variables and file locking.

php does not seem to be setup properly to query system environment variables. The test with getenv(“PATH”) only returns an empty response. Please check the installation documentation  for php configuration notes and the php configuration of your server, especially when using php-fpm.

and

Transactional file locking is using the database as locking backend, for best performance it’s advised to configure a memcache for locking. See the documentation  for more information.

You can go off trawling the documentation to resolve the issues, but in short it’s a simple config change for the php7.0-fpm and an install of the redis-server and php-redis php-apcu modules and a change to the owncloud config.

For php7.0 edit the file /etc/php/7.0/fpm/pool.d/www.conf and uncomment the env[PATH] line. Then restart the php7.0-fpm service.

Enable the PATH environment variable

$ sudo vi /etc/php/7.0/fpm/pool.d/www,conf
...
env[PATH] = /usr/local/bin:/usr/bin:/bin
...

$ sudo systemctl restart php7.0-fpm.service

Install Redis

$ sudo apt-get install redis-server php-redis php-apcu
$ sudo systemctl restart php7.0-fpm.service

Enable memcache.locking in Owncloud

Edit the file /var/www/owncloud/config/config.php

$ sudo vi /var/www/owncloud/config/config.php

...
'memcache.local' => '\\OC\\Memcache\\APCu',
 'memcache.locking' => '\\OC\\Memcache\\Redis',
 'redis' => array(
 'host' => 'localhost',
 'port' => 6379,
 ),
...

References

https://doc.owncloud.org/server/10.0/admin_manual/configuration/server/caching_configuration.html

https://doc.owncloud.org/server/10.0/admin_manual/installation/configuration_notes_and_tips.html#php-fpm