One of my clients has a QNAP 2-bay NAS that they store files on. They have 2x disks in a RAID1, it's an ext4 partition, shared using AFP with a couple of iMacs running Mac OSX Snow Leopard. They do backups to external hard disk from the NAS and rotate several disks.
Client accidentally pulled both hard disks from the NAS while it was running. Don't ask. The RAID1 array of course was destroyed. We opted to purchase 2x new disks and restore from backup (the new disks are enterprise disks, the old ones were junky little consider WD Black drives so it was just an opportunity to do the upgrade), and preserve the original disks in case we need to attempt some kind of re-assembly of the RAID array.
We've suddenly discovered that MANY, but not all of the files on the NAS have no extension, and they are unreadable. I tried attaching a single member disk from the RAID1 array to read it's contents, and the same files have no extension on the member disk, either.
Looking in our backups going all the way back to August 2014, the files seem to be this way as well.
Most of the files were originally InDesign, Photoshop, PDFs, Word documents, and TTF font files.
It seems to me like this has been ongoing for a long time, but even very recent files that the designer was working on just before the Christmas holidays appear corrupted, and the designer swears up and down that those files were readable prior to the incident with the RAID1 disks getting yanked.
The files seem to be the right size and when I open the document in a hex editor I can see that the contents does look to be intact so far as I can tell. Obviously something is still wrong with the content of the file, though.
We made some attempts to rename the file and put the correct extension back (e.g. putting a .docx extension onto a file that we knew was originally a document), but the programs stil couldn't open the file, Word thought the Doc file was corrupted. Although to be honest I don't really trust the designer's word for what format the various files were in.
Has anybody heard of this happening before? Any ideas what we can do to maybe figure out what happened, or analyze the files to see if there's a way to make them usable again?
Reading a bit on the Internet it seems that Mac computers sometimes neglect to put extensions on files and instead put marker data inside the file that identifies it's contents, but I'm not really sure how that stuff works. Maybe someone can fill me in.
--- Edit ---
I examined the beginning of a couple of the files in a hex editor. Screenshots are attached. Maybe somebody else can make heads or tails of what the format of these files could be so that I can check if they are intact?