I recently came across the dreaded owncloud login loop. This surprised
me a little, as I hadn’t performed a software upgrade or otherwise
changed any configuration parameters for a while.

So why the change?

One lesson I have learned long and hard through developing web sites and
testing, is that there are two components which are equally
important: program code and data. Never assume there is
something wrong with your code; your live data (or test data) could be
equally at fault, causing your application to slip up.

In the case of ownCloud, I found that my hosting environment had reached
its quota. Although ownCloud could create session files in /tmp, it
couldn’t write data to them. Perhaps the code should have handled this
more gracefully, but it’s safe to assume that a cloud environment
has hard disk space in order to save its files. That’s what it’s
there for, after all.

So here’s a quick, work-in-progress checklist to ensure your ownCloud installation has the
best chance of working correctly:

• PHP Sessions should be enabled
• session.save_path in php.ini should point to a valid (writable)
  filesystem location
• Storage space on hosting environment should be ample

More to follow when I have further issues..!