I was reading trough the link on journaling-filesystems and i would like to know where exactly is the journal stored in my Harddisk.
Some pointers on this image shown below
The journal is stored in a separate space of the partition, you cannot access it directly. You can use
sudo debugfs /dev/sda# where the
# symbol is the number of your partition, and then using
debugfs to print it out. The output is confusing though.
Generally, as a regular user, you don't need to know about the journal. Using
ext3/4 will be sufficient to prevent data loss (in most cases).
This link might help: http://www.linuxforums.org/forum/red-hat-fedora-linux/121074-ext3-journal.html
There is no fixed place for the journal, each filesystem stores it in a different place.
If you are expecting it to be a regular file, then your are mistaken, it's more like a part of the filesystem structure like the inode table. The funny point is that ext3/4 treats it exactly like a regular file. It is usually found in the inode number 8, but this is a kernel parameter that can be changed at compile time.
If you want to get technical, this article by Carlo Wood, written in March 2008, is a great read about the ext3 structure.
If you don't mind put journal in a place with words like partition table, inode or block and don't worry about it: