You can get to the command line on an e-smith server using either Alt+F1 or Alt+F2 when your in the administration panel.
Then you log in as root and there is your linux shell. Type mc to start Midnight Commander this will make it a lot easier to browse around the system and copy/delete/move files.
What you mean by accessing a H-disk? Is this the disk the user sees when he is logged in by his remote PC?
Normally e-smith takes up all the harddisks and gives them mount points, this is not the same as in the windows environment.
To access the database/files/mysql dir simply type the following line on the command line:P
ch database/files/mysql
thats if the dir is in the / dir. If not than you will first have to go to the directory in which it exists. Use the ls command to get a list of dirs and files.