I upgraded my owncloud server to 9.0.3 last night only to run into similar issues as in the past.
The first issue I ran into is I couldn’t log into owncloud. It gave me a white screen with a generic message on it to check the log files. It never said which log files or where they were located. Turned out they meant owncloud log file and it is located in the owncloud directory and not the usual log location for linux.
After reviewing the logs the problem was simple to fix. I just needed to edit an apache file. Once that was done everything was good to go until I ran into massive memory issues bringing my server to a screeching halt. This issue wasn’t necessarily an owncloud 9.0.3 issue. What happens is when you add Amazon S3 as an external location it does a crazy amount of “puts”. Yesterday I went from 29,000 to over 790,000 in less than 24 hrs. I thought this bug was suppose to be fixed. I will have to check github again. All these hits were killing the server. Removing the S3 locations fixed the issue but not after several reboots and waiting several minutes just to get into owncloud.
I know that the owncloud project recently forked but I will have to see some major improvements to switch. Owncloud is a great replacement to dropbox and they have come along way. Right now they are focusing on apps. I wish they would focus on shoring up a few other things first.