switch VLAN review

switch VLAN review

Switch evolution :

   Hub : 허브는 단순히 신호를 증폭 시키는 기능한다.

   Layer 2 switch : vlan을 이용해서 네트워크를 논리적으로 분리가능하다.

           But, 서로 다른 네트워크간에 트래픽을 보내기 위해서는 라우터가 필요하다.

          여기서 사용하는 라우터(router on a stick)가 병목현상을 만들수 있다.

   Layer 3 switch : 스위치에 라우팅 기능이 포함되어 있다. 라우터 없이 라우팅 기능을

                           사용할수 있다.

ECN(Enterprise Composite Network Model)

-       3 layer 모델 : Core – Distribution – Access

VLAN Foundateion

-       Vlan을 broadcast domain을 나눈다.  (segments broadcast domains)

Vlan configuration

Method 1 : vlan database

             모든 vlan 설정이 끝나고 exit 명령어가 실행될때 적용된다.

Method 2 : (config)#vlan 100

          (config-vlan) #name MARKETING

             각각의 명령어가 실행되는 순간 적용된다.

Interface 적용 방법ss

             interface range fa0/1 – 10

                           switchport mode acc

                           switchport access vlan 100

vlan 정보가 저장되는 위치 :  vlan.dat  stored in flash

In-Depth Trunking

Review : what is trunking?

             Trunking 포트는 멀티-vlan 트래픽을 전송할수 있다.

The Two tagging flavours

-       Inter-Switch Link (ISL) – 시스코 전용 프로토콜, encapsulation (add 26 byte + 4 byte)

-       802.1Q - 표준 프로토콜, inserts tag into frame ( only 4 byte )

 

native VLAN

만일, trunk 포트에서 태크가 없는 패킷으로 들어오면 스위치는 native vlan으로 할당한다.

PC는 태그 정보를 보내지 않는다. 따라서 PC가 보내는 패킷은 모두 native vlan으로 할당된다.

현재는 Hub를 많이 사용하지 않기 때문에 native vlan 개념이 voice over IP 에 이용된다.

일반적으로 많이 사용하는 IP폰에는 switchport가 있다. Network 관리자 입장에서 보면 IP폰과 PC의 트래픽을 분리하고 싶다. 따라서, 스위치 포트에 small trunk 기능 가지고 IPv폰과 PC트래픽을 분리한다. IP폰은 vlan 10 태그를 이용하고 PC는 태그없이 트래픽을 보내고 이는 스위치에서 native vlan ( 20 ) 에 할당하게 된다.

Negoticating Trunking : DTP(Dynamic Trunking Protocol)

스위치가 직접 연결되면 자동으로 trunk port 로 설정한다.

스위치 포트 5가지 모드 :

-       Access

-       Trunk

-       Dynamic Auto : DTP 메시지를 받으면 trunk로 설정하지만 먼저 요청 메시지를 보내지 않는다.

-       Dynamic Desirable : DTP 요청 메시지를 먼저 보내서 trunk로 포트를 설정한다.

-       Non-Negotiate :  DTP 요청 메시지를 받지 않고, 보내지도 않는다.  

 *** 실제 업무에서는 Trunk / Non-Negotiate 를 추천

Trunking Configuration

             Switchport trunk encapsulation dot1q

             Switchport mode trunk

             Switchport nonegotiate

             Switchport trunk native vlan XXX

             Switchport trunk allowed vlan 10,20,30

VTP (Vlan Trunking Protocol)

Revision 번호를 기반으로 Vlan 정보를 교환하는 프로토콜.

VTP mode : Server/client/transparent

VTP Pruning

자신이 가지고 있지 않는 vlan 정보는 trunk 포트에서 필터링한다.

아래 그림, GREEN 트래픽은 세번째 스위치에서 필터링된다.

우분투 12.04 - vi 환경 설정하기

우분투 12.04 - vi 환경 설정하기

vi 환경설정

우분투를 설치하면 기본적으로 설치되는 vim은 vim-tiny 버전이 설치된다. 때문에 기능상의 제한이 있을수 있다.

시냅틱패키지 관리자를 이용해서 vim 을 전체 버전으로 설치하자.

그 뒤에 각각의 홈디렉토리에서 .vimrc 파일에 자신이 사용할 vim 설정을 세팅해주면된다.

vim 세팅에 대해서는 인터넷 검색을 통해서 쉽게 확인가능하다. 아래 내용을 통해 기본적인 내용만 확인해 보자

내가 사용하고 있는 VI 설정

set autoindent      " 자동으로 들여쓰기를 한다.
set cindent         " C 프로그래밍을 할때 자동으로 들여쓰기를 한다.
set smartindent     " 좀더 똑똑한 들여쓰기를 위한 옵션이다.
"set textwidth=79    " 만약 79번째 글자를 넘어가면 \
"set wrap            " 자동으로 <CR>를 삽입하여 다음 줄로 넘어간다.
"set nowrapscan      " 검색할 때 문서의 끝에서 다시 처음으로 돌아가지 않는다.
set nobackup        " 백업 파일을 만들지 않는다.
"set visualbell      " 키를 잘못눌렀을 때 삑 소리를 내는 대신 번쩍이게 한다.
set ruler           " 화면 우측 하단에 현재 커서의 위치(줄,칸)를 보여준다.
set tabstop=3       " Tab을 눌렀을 때 8칸 대신 3칸 이동하도록 한다.
set shiftwidth=3    " 자동 들여쓰기를 할때 3칸 들여쓰도록 한다.
"set number          " 행번호를 사용한다.
"set fencs=ucs-bom,utf-8,euc-kr.latin1 "한글 파일은 euc-kr로 읽어들이며,유니코드는 유니코드로 읽어들이도록 설정
"set fileencoding=euc-kr         " 실제로 파일을 저장할때 사용되는 인코딩은 euc-kr
set background=dark " 하이라이팅 옵션
"set expandtab         " 탭을 입력하면 공백문자로 변환하는 기능을 설정
set hlsearch        " 검색어를 구문강조해주는 기능
set ignorecase      " 검색할 때 대소문자 무시하도록 하는 것.
set title " 타이틀바에 현재 편집중인 파일을 표시

"if has("syntax")
"   syntax on           " Default to no syntax highlightning
"   endif

.vimrc 예제 1

citylock$ sudo vi .vimrc

set number   :  줄번호
syntax on    :    문법에 색 넣기
set ai    :    자동행
set background=dark    :    바탕이 흑백일 경우 더 잘 보이게 한다
set si   :   if문 다음에 자동으로 맞추어주기
set tabstop=4   :   텝키의 간격을 4로
set shiftwidth=4   :   자동으로 맞춰주는 간격을 4로
set nobackup   :   백업을 만들지 않는다

.vimrc 예제 2

set autoindent      " 자동으로 들여쓰기를 한다.
set cindent         " C 프로그래밍을 할때 자동으로 들여쓰기를 한다.
set smartindent     " 좀더 똑똑한 들여쓰기를 위한 옵션이다.
set textwidth=79    " 만약 79번째 글자를 넘어가면 \
set wrap            " 자동으로 <CR>를 삽입하여 다음 줄로 넘어간다.
set nowrapscan      " 검색할 때 문서의 끝에서 다시 처음으로 돌아가지 않는다.
set nobackup        " 백업 파일을 만들지 않는다.
"set visualbell      " 키를 잘못눌렀을 때 삑 소리를 내는 대신 번쩍이게 한다.
set ruler           " 화면 우측 하단에 현재 커서의 위치(줄,칸)를 보여준다.
set tabstop=3       " Tab을 눌렀을 때 8칸 대신 3칸 이동하도록 한다.
set shiftwidth=3    " 자동 들여쓰기를 할때 3칸 들여쓰도록 한다.
set number          " 행번호를 사용한다.
set nobackup        " 백업파일을 생성하지 않는다.
set fencs=ucs-bom,utf-8,euc-kr.latin1 "한글 파일은 euc-kr로 읽어들이며, 유니코드는 유니코드로 읽어들이도록 설정
set fileencoding=euc-kr         " 실제로 파일을 저장할때 사용되는 인코딩은 euc-kr
set background=light " 하이라이팅 옵션 
set expandtab         " 탭을 입력하면 공백문자로 변환하는 기능을 설정
set hlsearch        " 검색어를 구문강조해주는 기능
set ignorecase      " 검색할 때 대소문자 무시하도록 하는 것.
set title " 타이틀바에 현재 편집중인 파일을 표시

if has("syntax")
   syntax on           " Default to no syntax highlightning 
endif


"=================== 로케일 설정 =================================
if has("unix")
    set encoding=euc-kr
elseif has ("win32")
    set encoding=cp949
endif

"======================= UTF-8, euc-kr 한글문서 그냥 열기 ====================
if v:lang =~ "^ko"
    set encoding=cp949
    set fileencodings=utf-8,cp949
    set guifontset=-*-*-medium-r-normal--16-*-*-*-*-*-*-*
elseif v:lang =~ "^ja_JP"
    set fileencodings=euc-jp
    set guifontset=-misc-fixed-medium-r-normal--14-*-*-*-*-*-*-*
    elseif v:lang =~ "^zh_TW"
    set fileencodings=big5
    set guifontset=-sony-fixed-medium-r-normal--16-150-75-75-c-80-iso8859-1,-taipei-fixed-medium-r-normal--16-150-75-75-c-160-big5-0
elseif v:lang =~ "^zh_CN"
set fileencodings=gb2312
set guifontset=*-r-*
endif
if v:lang =~ "utf8$" || v:lang =~ "UTF-8$"
    set encoding=utf-8
    set fileencodings=utf-8,cp949
endif




"================= Key 매핑 ========================

map <PageUp> <C-U><C-U> "맨 위로
map <PageDown> <C-D><C-D>  "맨 마지막으로
map <F2> :25vs ./<CR>   "F2: 탐색기 열기 
map <F3> :only<CR>    "창 최대화
map <F12> v]} zf "폴딩

"================= Gcc 컴파일 & 실행 설정 ==============

map <F9> :w!<cr> "현재 작업 저장
map <F10> :!g++ -W -Wall -O2 -g % -o %<<cr>  "컴파일
map <F11> :!%<<cr> "실행

우분투12.10] 컴퓨터 이름 변경하기

우분투12.10에서  컴퓨터 이름 변경하기

요즘에 vmware 를 많이 사용하다보니 OS를 설치하기보다는

기존에 설치된 OS 를 복사해서 사용한다. 

이 경우 한가지 문제점이 컴퓨터 이름이 모두 같다는 것이다. 

우분투에서는 아래와 파일의 내용을 변경해서 컴퓨터 이름을 변경할 수 있다. 

$sudo vi /etc/hostname

hosts 파일도 함께 변경해 준다.

$sudo vi /etc/hosts

우분투 12.10] 네트워크 정보 설정

우분투 12.10] 네트워크 정보 설정 

네트워크 설정 파일을 다음과 같이 변경한다. 

hadoop@ubuntuA:~$ cat /etc/network/interfaces
auto lo
auto eth0

iface lo inet loopback
iface eth0 inet static
address 172.16.10.10
netmask 255.255.255.0
network 172.16.10.0
broadcast 172.16.10.255
gateway 172.16.10.254

네트워크 재시작 

citylock@ubuntuA:/etc/network$ sudo /etc/init.d/networking restart

 * Running /etc/init.d/networking restart is deprecated because it may not enable again some interfaces

 * Reconfiguring network interfaces...                                          ssh stop/waiting

ssh start/running, process 2862

                                                                         [ OK ]

네임서버(Name server) 설정 

citylock@ubuntuA:/etc$ sudo vi resolv.conf

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)

#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

nameserver 127.0.0.1

nameserver 8.8.8.8

hosts 파일 수정 (/etc/hosts)

hadoop@ubuntuA:~$ cat /etc/hosts
127.0.0.1 localhost
172.16.10.10 master
172.16.10.11 slave01
172.16.10.12 slave02

Poisson Process - youtube

Poisson Process - youtube

Poisson Processes Definition and Intro

Poisson Processes Derivation

Queuing Theory lectures - youtube

Queueing Theory Lecture from youtube 

Today, I found good material for studying queueing theory which are easy to understand. 

the followings are the queueing lectures in youtube. Have fun... 

Intro to Queueing Theory

queuing lecture 1

queuing lecture 2

Hadoop 설치하기 on Ubuntu12.10

Hadoop 설치하기 on Ubuntu12.10

0. 설치 준비 

기본적으로 hadoop은 리눅스 기반에서 동작하기 때문에, 윈도우 VMWARE 에 우분투(ubuntu 12.10)를 설치해서 hadoop 을 설치 작업을 진행한다.

 - openSSH server 설치 : software center => Secure shell client and server 설치
 - JDK 다운로드 :  http://www.oracle.com/technetwork/java/javase/downloads/jdk6downloads-1902814.html
 - Hadoop 다운로드 : http://hadoop.apache.org/releases.html
     여러가지 버전중에 hadoop-1.0.4.tar.gz 를 이용해서 테스트 함 (stable)
   

이제 필요한 준비를 모두 된거 같아 하나씩 설치해 보자

1. Hadoop 용 계정 추가 

citylock@ubuntuA:~/Downloads$ sudo adduser hadoop
[sudo] password for citylock:
Adding user `hadoop' ...
Adding new group `hadoop' (1001) ...
Adding new user `hadoop' (1001) with group `hadoop' ...
Creating home directory `/home/hadoop' ...


2. Hadoop이 사용할 temp 디렉토리 만들기 

citylock@ubuntuA:/home/hadoop$ sudo chown hadoop.hadoop temp/

citylock@ubuntuA:/home/hadoop$ ll

total 36

drwxr-xr-x 3 hadoop hadoop 4096 Feb 20 06:14 ./

drwxr-xr-x 4 root   root   4096 Feb 20 06:10 ../

-rw-r--r-- 1 hadoop hadoop  220 Feb 20 06:10 .bash_logout

-rw-r--r-- 1 hadoop hadoop 3486 Feb 20 06:10 .bashrc

-rw-r--r-- 1 hadoop hadoop 8445 Feb 20 06:10 examples.desktop

-rw-r--r-- 1 hadoop hadoop  675 Feb 20 06:10 .profile

drwxr-xr-x 2 hadoop hadoop 4096 Feb 20 06:14 temp/

** hadoop이 실행되면 map, reduce 하는 과정에서 사용되는 temp 디렉토리

3. ssh 키생성후 authorized_keys 로 등록하기(비밀번호 입력없이 바로 접속할수 있다)

hadoop@ubuntuA:~$ ssh-keygen -t rsa -P ""
Generating public/private rsa key pair.
Enter file in which to save the key (/home/hadoop/.ssh/id_rsa):
Created directory '/home/hadoop/.ssh'.
Your identification has been saved in /home/hadoop/.ssh/id_rsa.
Your public key has been saved in /home/hadoop/.ssh/id_rsa.pub.
The key fingerprint is:
4e:34:7d:6d:81:a3:f7:77:03:61:73:8d:d4:9b:cb:78 hadoop@ubuntuA
The key's randomart image is:
+--[ RSA 2048]----+
|             ooo.|
|         .  o=.oo|
|        o ..o.* o|
|       . ....o o |
|        S  . .+ .|
|       o     ..Eo|
|        .     ..o|
|                 |
|                 |
+-----------------+

hadoop@ubuntuA:~/.ssh$ cp id_rsa.pub authorized_keys

hadoop@ubuntuA:~/.ssh$ cat authorized_keys 

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC7J1YY10OHCcH3C+uHyOpjFs2BkgPcS4Mn+gAd3yb05jgwqd1ff3vfzxwma3dsWeWehUNhnZOrvQmphJYQ+JNBsFPGaRLQxA2d8/YiLyrq9d3gj/NS+Es1JDO1hsPnbzHnLxacLvl0xayab9uYsFDX11tNJyTYQX+sc5GqIOaYyZwNYXh+04tSBPcW2ksIXCISvmpXwSV2Rp9UAFTdf+nHIKPuu8nDsJzHCHIRghFjRkS0awP7LsUMPY4oerAQtKa0dd16cMN1J4LW0Nfci4k+WT5IomlJtv3BWuod1wTNxVHgzy8qsdGO2x6tLhEE0GwNHLkU2++g98oEdJtCGPkZ hadoop@ubuntuA

이렇게 생성된 authorized_keys 파일을 slave 서버의 ~/.ssh/ 디렉토리에 복사한다.


4. 다운로드 받은 hadoop package 압축풀기
hadoop@ubuntuA:~/Downloads$ tar xvfz hadoop-1.0.4.tar.gz

hadoop@ubuntuA:~/Downloads$ mkdir ../bin
hadoop@ubuntuA:~/Downloads$ mv hadoop-1.0.4 ../bin/
hadoop@ubuntuA:~/Downloads$

hadoop@ubuntuA:~/bin$ ln -s hadoop-1.0.4 hadoop
hadoop@ubuntuA:~/bin$ ll
total 12
drwxrwxr-x  3 hadoop hadoop 4096 Feb 20 06:38 ./
drwxr-xr-x 23 hadoop hadoop 4096 Feb 20 06:37 ../
lrwxrwxrwx  1 hadoop hadoop   12 Feb 20 06:38 hadoop -> hadoop-1.0.4/
drwxr-xr-x 14 hadoop hadoop 4096 Oct  2 22:17 hadoop-1.0.4/

5. JAVA - JDK 설치하기

hadoop@ubuntuA:~/Downloads$ ./jdk-6u41-linux-i586.bin

hadoop@ubuntuA:~/Downloads$ sudo mv jdk1.6.0_41 /usr/local/
hadoop@ubuntuA:~/Downloads$ cd /usr/local/

drwxr-xr-x  8 hadoop hadoop 4096 Feb 20 07:25 jdk1.6.0_41/

hadoop@ubuntuA:/usr/local$ sudo chown -R root:root /usr/local/jdk1.6.0_41/
hadoop@ubuntuA:/usr/local$ sudo ln -s jdk1.6.0_41 java-6-sun


6. JAVA 및 HADOOP 환경 변수 설정

.bashrc 파일에 아래와 같이 환경변수를 추가한다.


export JAVA_HOME=/usr/local/java-6-sun
export HADOOP_HOME=/home/hadoop/bin/hadoop

export PATH=$JAVA_HOME/bin:$HADOOP_HOME/bin:$PATH

7. Hadoop 환경설정 파일 

/home/hadoop/bin/hadoop/conf/hadoop-env.sh 파일에서 JAVA_HOME 에 대한 부분을 수정한다.

# The java implementation to use.  Required.
export JAVA_HOME=/usr/local/java-6-sun

8. 기타 hadoop conf 파일 수정 


hadoop@ubuntuA:~/bin/hadoop/conf$ cat core-site.xml 

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://master:10001</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/home/hadoop/temp</value>
</property>
</configuration>

hadoop@ubuntuA:~/bin/hadoop/conf$ cat hdfs-site.xml 

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>dfs.name.dir</name>
<value>/hdfs/name</value>
</property>
<property>
<name>dfs.data.dir</name>
<value>/hdfs/data</value>
</property>
<property>
<name>dfs.replication</name>
<value>3</value>
</property>
</configuration>

hadoop@ubuntuA:~/bin/hadoop/conf$ cat mapred-site.xml 

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>hdfs://master:10002</value>
</property>
<property>
<name>mapred.system.dir</name>
<value>/hdfs/mapreduce/system</value>
</property>
<property>
<name>mapred.local.dir</name>
<value>/hdfs/mapreduce/local</value>
</property>
</configuration>

hadoop@ubuntuA:~/bin/hadoop/conf$ cat masters 

master

hadoop@ubuntuA:~/bin/hadoop/conf$ cat slaves 

slave01
slave02
master

9. Hadoop fs format 하기

hadoop@ubuntuA:~$ hadoop namenode -format

Warning: $HADOOP_HOME is deprecated.

13/02/21 02:38:59 INFO namenode.NameNode: STARTUP_MSG: 

/************************************************************

STARTUP_MSG: Starting NameNode

STARTUP_MSG:   host = ubuntuA/127.0.1.1

STARTUP_MSG:   args = [-format]

STARTUP_MSG:   version = 1.0.4

STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.0 -r 1393290; compiled by 'hortonfo' on Wed Oct  3 05:13:58 UTC 2012

************************************************************/

13/02/21 02:38:59 INFO util.GSet: VM type       = 32-bit

13/02/21 02:38:59 INFO util.GSet: 2% max memory = 19.33375 MB

13/02/21 02:38:59 INFO util.GSet: capacity      = 2^22 = 4194304 entries

13/02/21 02:38:59 INFO util.GSet: recommended=4194304, actual=4194304

13/02/21 02:38:59 INFO namenode.FSNamesystem: fsOwner=hadoop

13/02/21 02:38:59 INFO namenode.FSNamesystem: supergroup=supergroup

13/02/21 02:38:59 INFO namenode.FSNamesystem: isPermissionEnabled=true

13/02/21 02:38:59 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100

13/02/21 02:38:59 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)

13/02/21 02:38:59 INFO namenode.NameNode: Caching file names occuring more than 10 times 

13/02/21 02:38:59 INFO common.Storage: Image file of size 112 saved in 0 seconds.

13/02/21 02:38:59 INFO common.Storage: Storage directory /hdfs/name has been successfully formatted.

13/02/21 02:38:59 INFO namenode.NameNode: SHUTDOWN_MSG: 

/************************************************************

SHUTDOWN_MSG: Shutting down NameNode at ubuntuA/127.0.1.1

************************************************************/

** hadoop fs format 은 master 부터 시작해서 모든 slave 에서도 수행한다. 

** Directory 생성에 필요한 권한이 없는 경우 에러가 발생할수 있다. 

hadoop@ubuntuA:~$ hadoop namenode -format

Warning: $HADOOP_HOME is deprecated.

13/02/21 02:35:10 INFO namenode.NameNode: STARTUP_MSG: 

/************************************************************

STARTUP_MSG: Starting NameNode

STARTUP_MSG:   host = ubuntuA/127.0.1.1

STARTUP_MSG:   args = [-format]

STARTUP_MSG:   version = 1.0.4

STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.0 -r 1393290; compiled by 'hortonfo' on Wed Oct  3 05:13:58 UTC 2012

************************************************************/

13/02/21 02:35:10 INFO util.GSet: VM type       = 32-bit

13/02/21 02:35:10 INFO util.GSet: 2% max memory = 19.33375 MB

13/02/21 02:35:10 INFO util.GSet: capacity      = 2^22 = 4194304 entries

13/02/21 02:35:10 INFO util.GSet: recommended=4194304, actual=4194304

13/02/21 02:35:10 INFO namenode.FSNamesystem: fsOwner=hadoop

13/02/21 02:35:10 INFO namenode.FSNamesystem: supergroup=supergroup

13/02/21 02:35:10 INFO namenode.FSNamesystem: isPermissionEnabled=true

13/02/21 02:35:10 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100

13/02/21 02:35:10 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)

13/02/21 02:35:10 INFO namenode.NameNode: Caching file names occuring more than 10 times 

13/02/21 02:35:11 ERROR namenode.NameNode: java.io.IOException: Cannot create directory /hdfs/name/current

at org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.clearDirectory(Storage.java:297)

at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1320)

at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1339)

/hdfs 를 생성하고 hadoop 계정에 모든 권한을 준다. 

     sudo chown hadoop:hadoop hdfs

10. Hadoop 프로세스 실행 및 확인

hadoop의 모든 프로세스는 master node에서 컨트롤된다. 따라서 master node 에서 start-all.sh 스크립트를 실행하면 자신의 hadoop 프로세스 뿐만 아니라 ssh 로 slave 서버에 접속해서 관련 프로세스를 모두 실행시킨다.

master 서버의 프로세스 확인 (master & slave 기능)

hadoop@ubuntuA:~/bin/hadoop-1.0.4/bin$ /usr/local/java-6-sun/bin/jps
7532 Jps
6932 DataNode
6708 NameNode
7153 SecondaryNameNode
7456 TaskTracker
7234 JobTracker

slave 서버의 프로세스 확인 

hadoop@ubuntuA:~/bin/hadoop/bin$ /usr/local/java-6-sun/bin/jps
10696 Jps
10439 DataNode
10627 TaskTracker

참고사이트
http://coolkim.tistory.com/352
http://blog.softwaregeeks.org/archives/138
http://hadoop.apache.org/docs/r1.0.4/cluster_setup.html#Configuration

Ubuntu 12.10 일반 사용자에게 sudo 권한 주기

Ubuntu 12.10 일반 사용자에게 sudo 권한 주기



문제점 :


hadoop@ubuntuA:~$ sudo su -
[sudo] password for hadoop:
hadoop is not in the sudoers file.  This incident will be reported.

해결 방법 : 

/etc/sudoers 파일을 아래과 같이 수정하면 된다.


# Host alias specification

# User alias specification
hadoop ALL=(ALL:ALL) ALL

# Cmnd alias specification


적용후 : 


hadoop@ubuntuA:/etc$ sudo vi
hadoop@ubuntuA:/etc$

Resume 작성할때 유용한 표현들 

Sample Phrases and Suggestions

 

Communication Skills

• Excellent written and verbal communication skills
• Confident, articulate, and professional speaking abilities (and experience)
• Empathic listener and persuasive speaker
• Writing creative or factual
• Speaking in public, to groups, or via electronic media
• Excellent presentation and negotiation skills

Business/Sales Skills

• Possess entrepreneurial spirit
• Competitive attitude

Problem Solving Skills

• Combine patience, determination, and persistence to troubleshoot client issues
• Dynamic, results-oriented problem solver
• Easily understand and solve technical problems
• Handling complaints from parents, clients, customers, or citizens
• Skilled at evaluating options and generating solutions
• Strong problem-solving and analytical skills
• Troubleshooting equipment or situations

Multicultural/Diversity Skills

• Culturally sensitive and internationally traveled leader
• Experienced in successful management of diverse groups of people
• Proven adaptability to differing cultural and business environments
• Ability to talk and conduct business in __________ languages

Teamwork/Team Player skills

• Possess strong commitment to team environment dynamics with the ability to contribute expertise and follow leadership directives at appropriate times
• Thrive in a team environment and work well with others
• Enjoy working as a team member as well as independently
• Team leader and team player

Data Management/Office Organization Skills

• Calculating numbers
• Compiling data or facts
• Record keeping
• Updating information or records
• Well-versed in all aspects of customer conversion and accounting

Management/Supervisory Skills

• Able to lead others in high-demand situations
• Coaching, guiding, or tacking
• Delegating tasks or responsibilities
• Demonstrated leadership
• Evaluating performance, programs, processes, or events
• Extensive experience providing project management and consulting services in _______
• Group facilitating, managing group interactions
• Planning, budgeting, goal setting, or scheduling
• Proven leadership and organizational abilities
• Strongly committed to team-building and staff development
• Supervising people or processes

• A genuine desire to achieve, excel and evolve
• Ability to grasp new ideas and integrate them into desired results
• Ability to work independently in a fast-paced environment
• Able to coordinate several tasks simultaneously
• Able to handle challenges, with proven history of increased productivity
• Able to prioritize and operate proactively
• Analyzing situations or data
• Assembling equipment or data
• Commended for reliability and trustworthiness
• Committed to implementing quality improvement techniques
• Consistent record of forging strong relationships
• Constructing objects or buildings
• Coordinating activities or events
• Corresponding, answering, or initiating
• Counseling, advising, or listening
• Creating new ideas, new ways of doing things
• Deciding alternatives, resources, or material
• Designing products or form
• Displaying ideas, products, and equipment
• Editing newsletters, letters
• Enjoy working with public and diverse populations
• Establish genuine rapport with prospects and clients
• Estimating costs, income, or physical space
• Excellent common sense, judgment, and decision-making abilities
• Excellent interpersonal and analytical skills
• Excellent liaison and troubleshooting skills
• Extensive experience in _______________
• Fundraising one to one or through direct mail
• Goal-oriented and  results-driven
• In-depth knowledge of _______________
• In-depth understanding of emerging technologies and their commercial applications
• Inspecting or examining physical objects, financial statements
• Internship experience in related fields
• Interpreting data
• Interviewing
• Investigating private information, underlying causes, or sequence of events
• Making layouts for printed media or public displays
• Measuring
• Meeting the public
• Monitoring
• Motivating
• Observing physical phenomena, human behavior, or changing situations
• Operating equipment, machines, or vehicles
• Organized, goal oriented
• Organizing people, information, or events
• Organizing time or events
• Proficient in using technology to enhance data and information management
• Programming equipment
• Promoting
• Proven ability to maintain cost-effective operations
• Proven ability to run successful programs on ______________
• Proven history of improving operations and increasing profitability
• Proven track record of success
• Recording
• Remains calm in stressful situations
• Repairing equipment, vehicles
• Reporting
• Researching
• Results-driven professional with extensive experience in ______________
• Self-motivated, hard-working individual
• Self-starter, who applies individual initiative to get the job done
• Selling ideas, products
• Serving a product or individual
• Sketching pictures, diagrams
• Skilled at increasing profits and reducing costs by ______________
• Skilled in negotiations and people management
• Skilled staff trainer and motivator
• Strong educational background
• Strong interpersonal skills and positive work ethic
• Strong work ethic
• Successful record of leading teams
• Teaching formal or informal
• Top-producing sales expert with _____ years of experience in ______________
• Up-to-date with changes in technology and the business implications/applications of new technologies
• Well-developed skills in ______________
• With broad experience in ______________
• With cross-functional expertise in ______________
• Work independently, successfully meeting quotas
• Works efficiently under pressure
• Fully committed to providing the highest possible standards of customer service and support.
• Team leader with a proven ability to train, supervise, motivate, and evaluate customer service representatives.
• People oriented; enjoy working directly with customers and the general public.
• Self-starter; can be depended on to complete a task under minimal supervision.
• Understands and appreciates the importance of a job well done.
• Mechanically inclined: electrical, mechanical, plumbing, and automotive.
• Languages: fluently reads and writes English, Spanish and Italian.
• Excellent personal motivation with a proven ability to build and work collaboratively in a strong team concept environment, and independently.
• Focused, versatile, dependable, multi-task oriented, flexible, positive, emotionally stable, able to adapt effectively to challenging and emergency situations.
• Well developed skills in prioritizing, organization, decision making, time management, and verbal/written communication skills.
• Strong interpersonal skills resulting in exceptional rapport with people. Proven success in initiating, promoting and maintaining strong interpersonal relations. Able to deal courteously, professionally, and tactfully with the general public in a variety of circumstances.
• Qualified in Industrial First-Aid Level II application and care.
• Excellent analytical skills with the ability to analyze situations accurately and effectively.
• Strong computer skills in Microsoft Word and SPSS for Windows.

Example:

"Proven year background in sales with special emphasis on customer care. Solid track record in relationship and business management, developing and maximizing new business and marketing strategies. Excellent communication, leadership, motivational skills and can interact effectively with clients, business prospects and staff".

Example:

"An innovative marketing administrator and national events expert with proven creative and management ability in hospitality and entertainment. Able to conceptualize and launch marketing campaigns and successfully facilitate smooth running of major national events, delivering results on time and to impeccable standards. Aggressive, confident, well-spoken negotiator and solutions - evolver.

Example - (for someone changing careers):

"Expert administrator now seeking to harness twenty years' experience in recruitment, employee relations, and personnel management within a human resources capacity. Highly enthusiastic for this career change goal, and eager to proactively spearhead the long-term success of an HR department in the telecommunications industry"

Respected leader, equipped with powerful communication, coordination and analysis skills. Fully committed to providing and implementing dynamic, compelling solutions to the ongoing objectives of the charitable organization.

Works well in challenging, fast-paced, high-stress and deadline-oriented environments individually or as part of a team. Proficient in project management and digital technology as well as operational supply chains; also heavily experienced with customer and employee relationships as well as technical support. Knowledgeable in creating detailed reports, documents and presentations. Focused on consistent quality work and a desire to simplify and innovate the daily operations of corporate culture and the industries of music and technology.

Accomplished sales professional known for delivering strong revenue and profit gains in highly competitive markets, seeking a Regional Sales Manager position. Bring years of solid experience and select strengths that encompasses sales territorymanagement and key account development. Equally effective at relationship building, program development, and team leadership.

Accomplished management professional with experience in sales/marketing leadership positions. Record of success in developing campaigns, strategies, and solutions that have generated - and -figure revenue growth. Recognized for ability to build relationships with key personnel and close large sales in heavily competitive market.s Well-versed in sales lifecycles and skilled strategist/negotiator. Exceptional trainer and mentor with skills to motivate peak individual performance from team members while driving sustained forward growth momentum

Areas of expertise include:

Outgoing campus leader and successful fundraiser ready for the challenges of a full-time marketing position with an emphasis in market research and product planning. Biologist employing creative strategies to integrate environmental science into elementary classrooms. Success in developing parent and community partnerships for a practical application of science unit.

출처 : http://www.enmu.edu/services/counseling/resume/phrases.html