==== File System Performance ====

[[http://www.redhat.com/magazine/008jun05/features/schedulers/|File System Scheduler]]
==== State Of Process ====
<code text>
d : uninterruptible sleep (usually io)
r : running or runnable (on run queue)
s : interruptible sleep (waiting for an event to complete)
t : stopped, either by a job control signal or because it is being traced.
w : paging (not valid since the 2.6.xx kernel)
x : dead (should never be seen)
z : defunct ("zombie") process, terminated but not reaped by its parent.
</code>
==== Init Runlevel ====
<code text>
0	Halt
1	Single-User mode
2	Multi-user mode console logins only (without networking)
3	Multi-User mode, console logins only
4	Not used/User-definable
5	Multi-User mode, with display manager as well as console logins
6	Reboot
</code>

==== Named ====

First Block explained.
<code bash | example.org>

$TTL 3600        ; 1 hour default TTL
example.org.    IN      SOA      ns1.example.org. admin.example.org. (
                                2006051501      ; Serial
                                10800           ; Refresh
                                3600            ; Retry
                                604800          ; Expire
                                300             ; Negative Response TTL
                        )

</code>

=== Magic Number ===
this is considered magic serial number because.\\
as soon as your set this number DNS reset it's counter.
<code text>
2147483647
</code>

==== File Permission notation ====
<code text>
- denotes a regular file
d denotes a directory
b denotes a block special file
c denotes a character special file
l denotes a symbolic link
p denotes a named pipe
s denotes a domain socket
</code>