Saturday, August 18, 2012

Compacting Data loss.

Data loss through the compact process has become the number one support request, so something is wrong.

The release of Thunderbird 16 should have fixed most of these issues.  Please post a support request on the get satisfaction support site if your still experiencing these sorts of issues,

Please be sure to try right clicking the folder selecting properties and then repairing it. (not this only repair the index,  If real data loss has occurred it can do nothing) Lots of information about how and what is always good.  Steps to reproduce a problem get it fixed far faster that those issues where magic is involved.

Unfortunately no one knows what it is that is wrong, or really when it 'became' a problem.  I have posted in the past about compacting and stated that data loss does not occur at the time of compacting, at the moment I feel that is not the case.  I may also have been in error then as well.

I am making no claims that I can fix your problem, or that your data can be restored, on the contrary, recent cases of data loss do appear to be permanent.  The usual options of changing the entry on the View menu for folder to ALL does not work and neither does right clicking the folder, selecting properties and then the repair button. I do however encourage everyone to try them.  At this point my desire is to try and establish some sort of base line that can be used to determine the cause.

Is there a fundamental bug in the compact process?  If there is, it is well hidden.  Millions of people have no problem, but an unfortunate few not only see this problem, but in some cases see it repeatedly.  This leads me to believe, rightly or wrongly that there is a secondary issue required or more than one that makes the circle complete and result in the problem.   Thus we need to start looking for similarities between users who have the problem, and we get to the whole point of this post, to ask people to provide information.

I have no idea if this will be useful, but your co operation is appreciated.


  1. Great idea Matt!
    It could be good to post the link of this survey in the threads tag "compactlost" on GSFN

  2. My entire Inbox disappeared after selecting "compact now" in response to the compact folders pop-up message in T-bird. I attempted to "repair folder" from the file properties menu with no luck. However, I found I was able to recover my Inbox using the "restore previous versions" option in Windows 7 after navigating to the folder containing the Inbox file. That data was only a couple of days old. I hope others find this useful.

  3. It wasn't just my Inbox. Entire folders went missing. Two were for emails from environmental groups I support. One, called Personal, had all email from friends and family, including a folder of emails from my wife back when we were first dating. This is serious stuff. It's as if you have reached into my life and burned documents that I value.
    If you can't find the problem, then at least have TB back up the emails somehow before compacting, and provide an easy way of getting them back if something goes wrong.

    1. Backup is your problem. It is supposed to be something we all do with things we value.

      I am sorry if you have lost data, but don't blame anyone but yourself for failing to backup your data. If it was not a software issue, it would be a failed hard disk oe an em pulse from a lightning storm.

    2. Well, Matt, clearly you have other issues... I wonder what you'd say if some other software deleted your data with no warning and those programmers behind it spent a few years trying to figure it out, then blamed you. My intent was merely to point to a simple work-around that could be implemented by the programming community; perhaps it's more difficult than I thought. It is the sort of thing my students could program, but I do not know the details behind TB's file structures etc.
      On a brighter note, here's an odd event that may help in tracking down the problem. As I mentioned, several of my folders and their sub-folders went missing at the same time as the Inbox contents. Since I have filters set using those folders, I re-created them, with the same names as before, e.g. Personal. When I did, any sub-folders came back within the newly-recreated folders. Even though the new folder has no email in it, the sub-folders all do. Clearly, the sub-folders still existed all along, and something (a pointer?) survived to indicate where those sub-folders belonged. I do hope this helps, as I've been using TB for years now, and strongly prefer it.

    3. And by the way, there is no built-in backup facility in TB. I use MozBackup. A built-in backup facility would be way more use than, say, yet another chat facility.

    4. you get no argument from me. that is why I have a blog post on the subject Personally I prefer the beta stand alone profile manager.