installing from source and why tar?
 

i have the source of mysql. when i try to install it using the command: rpm -i mysql.src.rpm
i get an error like:cannot write to /usr/src/rpm/sources.

when i checked the properties of the /usr/src/rpm/sources directory, the write right was restricted to root.

i use mandrake8 and by default the login is my username. how can i login as root instead of the default username-when the mandrake login screen does not allow me to type in the username at all and only allows me to type in the password?

Second question:
I know that the tar command is used to archive and the gzip command is used to compress. but why use tar at all? what is an archive(in relation to files)? why should i archive my file?

you can get root rights by the 'su' command
In a terminal:
su
(type password)

et voila

A tar.gz beats downloading a zillion gzips. *g* Though you can concatenate multiple zips. Plus I think tar creates an archived copy by default and gzip deletes the original by default. I suspect, but don't recall, that they handle permissions and timestamps on the files differently, too. Tar was originally for tape archives. Just the usual *nix hyper-flexibility and inertia of custom, I suppose. Applying the right options to either would have the same effect as a different string of options on the other in most cases. *shrug*

Re: installing from source and why tar?
 

Which user were you logged as when you tried the command? If you were your normal user, use 'su' (as suggested above):
1. Open a terminal
2. Type 'su', press Enter. You'll be asked for root password, enter it.
3. Cd to the right directory and run 'rpm -i mysql.src.rpm'.