Reader Phil Chenevet wrote to ask:
Question for your newsletter perhaps although it is sort of an esoteric. It has to do with RAW file and other file types.
I encrypted a 40GB external drive with TrueCrypt 6.0, an open source encryption program that has been around for years and was thought of as very well tested and widely used. The encrypted drive or volume is simply ‘mounted’ and all data becomes visible and usable and when you are finished, you ‘unmount’ it and all data is encrypted again. Amazing but true.
I moved data in and out of this drive for several months with no problem until the headers apparently became corrupted and there was no way to mount the volume. Luckily they built in a backup header just for this situation and I was able to ‘mount’ the volume again but sadly, the data inside stayed encrypted.
OK, here is my real question: Special recovery software could see the RAW files and made a backup of them, putting them into four directories or folders, DIRO.GZI (FILO.GZI; FIL1.GZI; FIL2.GZI)
DIR1.JPG (FILO.JPG; FIL1.JPG; FIL2.JPH; FIL3.JPG)
DIR2.ARJ (FILO.ARJ THRU FIL7.ARJ )
DIR3.TOC ( FIL0.TOC; FIL1.TOC)
My question has to do with those GZI, ARJ and TOC files. What are they? THey are obviously compressed, can they be opened? Just trying to expand my knowledge of computer stuff here because I have little hope of getting my data back.
Thanks, A Retired Louisana Guy
Philip has experienced one of the reasons why I never use disk compression utilities to "make my drive hold more stuff" and why I don’t like encryption systems for drives.
Similarly, I don’t like programs like GoBack (which was installed as part of Windows Me) which mess around with the partition ID on a hard drive so that utilities only work if the drive booted loaded that particular utility program.
Since I’ve never used TrueCrypt, so I’m going to have to do some guessing…
ARJ is a type of file compression. I’m not sure what’s in the compressed files, but it may even be folders with more files and subfolders in them.
GZip is another type of file compression, although it’s usually abbreviated as .GZ instead of .GZI . Similarly, it can contain files or folders, files, subfolders, more files, etc.
TOC usually means Table Of Contents — perhaps an index to all the actual files embedded into the other files
Phillip should be able to open .arj and .gz files using FilZip (www.filzip.com) or 7Zip (www.7-zip.org).