Export from mongo database file to bson - mongodb

Question

I have a mongo database db.ns, db.0, db.1, ... db.7
Accidentally I remove all the data from a collection, but in the database files (explorer with vim) it's all (or part of) the data.
After trying to recover the data moving to another mongodb instance, or mongod --restore, also, I try with the mongodump, but the collection appears empty.
I try to recover from scratch, directly from the files. I try with bsondump for each one, and for a single file (cat db.ns db.1 ... > bigDB) but nothing.
I don't know what other ways are from recover the data from a mongo database file.
Any suggestion?? Thx!!!

Answer 1

[SOLVED]
I will try to explain what I do to "solved" the problem.
First. Theory.
In this SlideShare, can see a little of how files MongoDB database work.
http://www.slideshare.net/mdirolf/inside-mongodb-the-internals-of-an-opensource-database
Options:
When you remove accidentally a collection:
the first thing that you have to do is quickly copy all the database (normally in /data/db or /var/lib/mongodb) and stop the service.
Remove the journal directory try to recover from this copy and pray ;D
You can see more about that, here:
mongodb recovery removed records
In my case, this did not work for me.
In Journaly case, mongo no update its database files directly only their indexes.
So that, you can access to the files (appointed as database.ns, database.0, database.1 ...) and try to recover this.
These files are as cleaved BSONs and binary. So, you can open, and see all the information
In my case, I create a easy function in PHP that first read the file, and explode the file in smallers files.
Before, takes one to one and apply some regular expresions to remove Hexadecimal values, explode the info into the registers (you can see the "_id" key to do that) and do some others task to clean the info.
And finally, I have to process manually all the preprocessed info to obtain all the information.
I think, I have lost, at least, the 15-25% of the information. But I prefer to think that I have recovered the 75% of the lost info.
Caution:
This is not a easy and secure way to solve this problem. In my case, the db only recive information, and not modify or update this.
With this method, a lot of information will be lost, Mongo IDs, integers, dates, can't be recovered.
The proccess is 100% manually, you can spend your time on automating certain tasks, but will depend on your database structure.