I am just testing Wuala. I am going to dump it for something better due to its acquisition by American Seagate, but I have already uploaded some files to Wuala and it will be easier to migrate if I sort out all sync issues first.
I noticed that Wuala shows sync icon on one of my archive folders constantly. The folder doesn't change anymore, which made the constant syncing suspicious. I opened Sync Overview in Wuala only to see that the sync is "In Progress".
I've looked around on the Internet and the recommendation was to export logs from Wuala. So I went into Sync Overview again, selected the failing sync, clicked "Show sync status", and then clicked "Create log".
I opened the ZIP file containing logs, found the log file pertaining to the failing sync and there was a message like this:
2014-04-19 18:54:30 Found change: CREATION at /Archive/2013/bla_bla.doc
2014-04-19 18:54:30 Change Reason:S: Local [1293452837050,19968]-T: Wuala [0,-2]-E: [0,-2]
The message repeated over and over again. Apparently Wuala was trying to sync that file repeatedly, but it kept failing. So I looked further and found this in Executor.log.txt:
2014-04-19 18:54:30 Personal: Failed to execute 'CREATION' at '/Archive/2013/bla_bla.doc'
2014-04-19 18:54:30 Path:/Archive/2013/bla_bla.doc Side: Wuala Message:IO
2014-04-19 18:54:30 Cause:
obf.aNP: Path:/Archive/2013/bla_bla.doc Side: Wuala Message:IO
Caused by: java.io.IOException: null
Caused by: obf.aNP: Path:/Archive/2013/bla_bla.doc Side: Local Message:File is used by other process, delay sync job
Caused by: java.io.FileNotFoundException: C:\Users\Robo\Documents\Personal\Archive\2013\bla_bla.doc (Access denied)
The first thing I have noticed was the message "File is used by other process", but that turned out to be bullshit conjecture logged by Wuala, because the file for sure wasn't used for anything, especially after fresh reboot. Occasionally, antivirus or backup software causes such errors, but that wasn't the case, because the error was persistent.
So I took a look at the "Access denied" message, which looked like it was generated by Windows and thus much less likely to be bullshit. I've thought that maybe there's something special about the file, so I went into file properties and it turned out it was the only file that was for some reason marked as read-only. I unchecked the read-only option and Wuala sync was OK in a minute. Problem solved.
This experience tells me something about Wuala. I can personally confirm that Wuala is buggy as is widely claimed. Wuala's focus on security prevents their developers from collecting telemetry that would allow them to fix bugs before they are reported. Wuala has to rely on volunteers to report bugs and submit their log files. The process is rather thorny, which means the report-to-sulking ratio will be around 1:10,000. Not to mention the low quality of reports, which is another obstacle to fixing bugs.
Client-side encryption has its downsides. It's not just much more difficult development for the provider. The list of weak spots includes the lack of features that rely on server's ability to decrypt the data, lack of any sane method to recover lost passwords for the less sophisticated users, and generally lower efficiency of the whole service that results in higher prices and lower storage quotas. I am nevertheless decided to use client-side encryption until this world finds some way to make these services trustworthy.