kernel-source and kernel-header?

Hi all, i want to compile and install a new kernel. Using aptitude to search the "kernel" package, i find there are "kernel-source" and "kernel-header" packages. Should i install the both kernel "source" and "header" to install the new kernel? Another interesting question: if i inst

System user accounts lost after system halt

Hi all, After a system halt, i find all the users in my system seems been lost. I can't login in as any id. I tried to use linux single mode to boot. but after system setup, the system give me a prompt said "you have no name". I find my "/etc/passwd" file has become a binary file full of