FHS Flashcards
/boot
The OS Kernal - contains the actual operating system, and other files required by the boot loader (LILO or GRUB)
vmlinuz
The linux kernal, located in /boot
contains the actual operating system, and other files required by the boot loader (LILO or GRUB)
/bin
/bin
General Utilities - most important executable programs (mostly system programs) which are nescessary for the file system to boot. Includes mount and mkdir. Also contains programs that are nescessary to get a damaged system running again if only the file system containing the root directory is available.
Where is mkdir, the system program, located?
/bin
Difference between /bin and /usr/bin
/bin has files required on boot and system repair, /usr/bin has additional programs not required in that respect.
/sbin
“special system programs” - Like /bin, /sbin contains programs that are nec- essary to boot or repair the system. However, for the most part these are system configuration tools that can really be used only by root. “Normal” users can use some of these programs to query the system, but can’t change anything. As with /bin, there is a directory called /usr/sbin containing more system programs.
programs that are nescessary to boot or repari the system, but for the most part are only really used by root
/sbin
/lib
System Libraries - This is where the “shared libraries” used by programs in /bin and /sbin reside, as files and (symbolic) links. Shared libraries are pieces of code that are used by various programs. Such libraries save a lot of resources, since many processes use the same basic parts, and these basic parts must then be loaded into memory only once; in addition, it is easier to fix bugs in such libraries when they are in the system just once and all programs fetch the code in question from one central file.
/dev
Device Files - forms the interface betwenn the shell and to the device drivers inside the kernel.
what is a character device
Device that processes single characters. eg. mouse, keyboard, terminal
what is a block device
device that processes characters in block (eg of 512 bytes), such as hard disks, zip disks, etc
how are device files outputted in ls -l?
as b or c for block or character device.
where can you discard output that you will never need?
/dev/null
/dev/null
a ‘dust bin’ for discarding output
/etc
config files - v important! - contains configuation for most programs.
/etc/fstab
describes all mountable file systems and their properties
/etc/hosts
one of the configs for TCP/IP network. Maps the names fo network hosts to their IP addresses.
/etc/inittab
config for init program and thus for the system start
/etc/init.d/*
dir for the “init scripts” for various system services. Used for startup/shutdown when the system is booted or switched off.
> red hat uses /etc/rc.d/init.d
/etc/issue
contains the greeting that is output before a user is asked to log in. Frequently contains the name of the vendor that installed.
/etc/motd
contains “message of the day” that appears after a use has successfully logged in.
/etc/mtab
lists all mounted file systems and mount points.
/etc/passwd
list of all users that ore known to the system, with various user-specific info.
/etc/shadow
encrypted passwords for users, not readable by normal users.
describes all mountable file systems and their properties
/etc/fstab
