The 624 packer is a executable packer that got released in 1997 by Kim Holviala. It only supports DOS .com files and was targeted to compress 4kb demoscene intros but offers a decent compression of files from 1 kb to 20 kb size. Uses LZSS (Lempel–Ziv–Storer–Szymanski) compression algorithm The assembly unpacking stub is 127 byte small Fixed length huffmann codes are used to store the length and offset of a match Packed data is stored as a bit stream.

The goal of this tutorial is to show a way to backup and restore a MongoDB without the need of using file system snapshots by only using MongoDB shipped tools. In my case I did not have the option to use LVM snapshots, which would have been my primary choice. The restored Cluster will have the same distribution of chunks like it was when the backup was done. My MongoDB cluster setup looks like this:

The following list contains some facts and problems that I stumbled across in my MongoDB journey. It was a good lesson on what problems you can face in a production environment when you or your company decide to jump onto the latest Hype Train of technology. Fool me once, shame on you; fool me twice, shame on me. I will update this post from time to time to mark the fixed problems - the current speed is 1 fixed ticket per year.

When going back down memory lane about my programming projects the first memory that comes up is developing software under DOS. The simple way of writing programs as .com files allowed for a lot of fun stuff like coding size competitions. Those executable files did not include any header and got executed as code starting from first byte of the file. My favorite production of the old days is this 29 byte small intro that I developed 2001 using assembly language.