Sunday, February 03, 2013

The Case of the Disappearing Files

So Friday was a relaxing day where many were on leave, including the boss. Although the finance head in one of our business units did give me a face to face friendly warning about the stamping duty late penalty incurred (Note to self: stamping must be done within 30 days form the date of the instrument, not 1 month). It's funny how people expect me to recognise them when I hardly ever (or haven't even) meet them. My brain will have to quickly sift through the clues I could use for recognition, e.g. lanyard, topic of discussion, name, voice... Anyway, this is not what this post is about.

So, on Fridays we usually walk over to the mall for our lunch. I had been given a minutes writing assignment in the morning and had started on it before lunch. As usual, I had left my work open on my desktop, but had locked the computer.

When I came back from lunch, I found that our shared drive was "disconnected and not accessible", which sometimes occurred. However, when I decided to continue my work, I found that all my files in certain folders on my USB drive were missing! Panic!

First thought that came to mind was, "did someone access my computer while I was away and delete my files?" Not everything was gone, only all the work that I had took home since starting this job was missing and some others from my previous company. This was very suspicious - sabotage? But my mind was too twisted.

Next thought was, " maybe there's a virus on my USB drive - transferred from my superior's PC when she was transferring the sound files?" Then I was afraid to continue using my USB drive. But scanning the drive and my PC's hardrive yielded no threats found. I was telling myself that I needed to go home and open the USB drive using the Mac to see whether there were any suspicious EXE files in it and delete, delete, delete!

But a funny thing I'd noticed was that eventhough the files were missing, the USB drive's capacity was maxed out. If a deletion had occurred, it would result in some clearing of memory space. But that was not the case. The files were gone but the space was still occupied.

So I turned on the 'view hidden files' settings. But still the files were missing. I didn't want to ask for the sound files again as it would look bad on me that I had lost all 6 files just hours after being given them. (As if I needed another reason for creating a bad impression on my boss)

After perusing all the options Windows had for me in Windows Explorer, I came to one option for file recovery. With nothing else to lose, I tried it and to my delight a whole list of recovered fragment files were restored. All the files had CHK extensions and were serially named, thus leaving me with no clue of their identity.

Since I had experienced file recovery before during my UK/US trip (due to accidental deletion of my Dubai photos), I knew that the fragmented files had a good chance of being corrupted due to possible truncation of the starting and ending scripts (excuse the non-tech term, but I just know that those scripts identify what type of file it is to the computer). So without those scripts, the computer cannot identify what it is and the file is considered corrupted - cannot be opened by programmes.

I googled for info on how to recover these CHK files and a solution was to rename the extension on a trial and error basis. So I did just that and voila! I found back some of my missing files - including the 6 sound files I had "lost"! So happy of my troubleshooting! So began the tedious task of trying to guess the file type from the size of the CHK files. For those that I was not too sure about, I renamed them as TXT files to open them up in Notepad and find clues of its identity. Unfortunately, all the PDF files recovered had been corrupted - although their script had identified them as PDF files, when renamed the PDF reader still couldn't open them. Word and MP3 files were restored flawlessly (as yet). The PowerPoint files had some linking errors but were functional, which was good enough for me.

I haven't gone through the whole list of CHK files yet, but probably will not waste time on them as they are not vital files. But note to self: don't leave USB drive plugged in when going away from the computer for an extended period of time. I had read that this could have happened due to improper disengagement of the drive (e.g. unplugging the USB drive without using the 'safely remove hardware' feature @ stopping the device before removing), but in my case it could've been some sort of technical glitch (note the inability to access shared drive mentioned earlier) or my chair could've knocked the USB drive while I was going off. I don't know the true cause, but I'm happy that my sound files are recovered and a-ok! ;)

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