My clients have experienced last friday strange loss of data from my application.
The app works with almost 200 files, but at any given moment only 20 are actually open. So, they were working in it, at some point there was a surge in power, the lights blinked once, the screen turned off, but computer continued to work. As they tried to save, application reported an error and on relaunch all the documents were missing.
They called me and I connected over remote access and this is what I found: 36 files (that should have had content from the documents they entered since March) were 4K in size (i.e. empty, only few bytes in use, all zeroes). These files had all creation date March 1st and modification date Apr 15, 17:20. The rest of the files, never used as it seems, had both creation and modification at Mach 1st. Those files that were never used were 4K in size too, but their content was not zeroed out. They had proper header content at the beginning.
There is a file that keeps record of changes/transactions, but that file is empy too.
What could have happened? I have the same application on several hundred other places and never, ever anything similar to that ever occured. On power loss, maybe one or two records would disappear sometimes, most of the times everything would be just fine. This makes no sense to me. Or maybe it should? I have this app on Mac OSX and Windows and I never experienced anything similar to this.
Is it something related to hardware? Maybe some strange drive configuration, something in OS, some strange settings (XP SP2). They don't have a fresh backup, of course. Bad luck?