LAB THC HNH LINUX

GII THIU:

Trong lab ny s tm hiu h iu hnh linux qua gip ta hiu r hn v hot ng ca h iu hnh ny v c th hn l CENTOS. Bi Lab ny s hng dn c th cch hot ng ca CENTOS nhng ng dng ca n cng nh l li ch trong vic s dng CENTOS.

NI DUNG THC HIN:

Ni dung gm 9 phn, mi phn l mt hng dn c th thc hnh linux CENTOS

1. Ci t linux CENTOS2. H thng tp tin th mc3. Ci t phn mm, tnh tin ch v cch dng4. Qun tr ngi dng5. Qun l tin trnh6. Qun l ti nguyn cng7. Cu hnh mng v thng k lu lng8. Ci t v s dng Samba ( Hng dn s dng DNS, WEBSERVER,

DHCP, FTP, MAIL SERVER)9. Lp trnh SHELL trn Linux CENTOS

LAB 1: CI T LINUX CENTOS

I/ CI T:

CENTOS gm c 6 a CD l y cc gi nht nhng ta cng c th ci t 5 a sau ci cc gi cn thiu qua internet cng c.u tin ta khi ng PC ch boot CD, ta b a u tin voKhi chng trnh ci t khi ng, s hin th mn hnh ny

C th chn cc ch ci t sau: : chn ci t ch haLinux text : chn ci t ch text (text mode)Ngoi ra nu mun chn mt s ci t khc ta nhn phm F2 (option)Nh vy ci t bnh thng ta nn nhn ENTER s hin ra hnh ny

Nu mun kim tra ti nguyn a th chn OK, nu khng mun th chn SKIP. Kim tra a gip ta pht hin li v trong qu trnh ci t nu c mt a b li th s b ci li qu trnh ci t . cho nhanh ta chn SKIP. Ta ch i dn hnh ny

Tin trnh ci t bt u, chn Next

Chn ngn ng trong qu trnh ci t, ta nn chn English v bm Next

Chn bn phm thch hp, ta nn chn U.S.English ri chn Next

y l bn cnh bo t chc phn vng trn a ci t CENTOS, ta nn chn Yes phn vng a cng cn ci t Centos

phn chia cng cho ng ta cn nm r nhng iu sau: Remove all partitions on selected drivers and creat default layout : khi ta mun

loi b tt c cc patation c sn trn h thng. Remove linux partitions on selected drivers and create default layout : khi ta mun

loi b tt c cc linux partitions c sn trn cng Use free space on selectde drivers and create default layout : s dng vng trng

cn li ca a cng chia partition. Create custom layout : phn chia partition bng tay (ta nn chn ci ny)

Bm Next

Ta bt u vic phn chia partition:Chn New: to partiotion mi, linux bt buc ti thiu phi to 2 partition sau:

Partition chnh cha th mc gc (/) v ht nhn (kernel), partiontion ny gi l Linux Native Partition

Partition Swap c dng lm khng gian hon i d liu khi vng nh chnh c s dng ht. Thng thng kch thc ca partition Swap bng 2 ln kch thc ca vng nh chnh (RAM)

Edit : sa patition Delete : xa patition Reset : phc hi trng thi a trc khi thao tc RAID : s dng RAID (c ti thiu 3 cng) LVM : s dng vi Logical Volume Management

To cc partition sau:Chn New to patition swap

Chn File System Type : swapChn Size: 1024 (gp 2 ln RAM my tnh ca mnh) nh hnh

Nhn Ok

Tip theo chn New to patition /bootChn Mount Point: /bootChn File System Type : ext3Chn Size: ty

Nhn OKChn New to patition root (/)

Chn Mount Point: /Chn File System Type : ext3Chn Size: ty

Chn OK

Chn NextTip theo ta ci t chuong trnh boot loader GRUB v t password cho boot loader bng cch:

Chn dnh du chm vo The GRUB boot loader will be install on /dev/sda.

Chn check box Use a boot loader password->chn Change password

Nhn vo mt khu bt k v bm OK.Sao chn Next.

Chn Edit cu hnh Network Devices hoc automatically via DHCP nhn IP ng t router internet. Sau khi chn xong ta bm Next.

y l phn chn khu vc a l ca h thng y ta chon Asia/Saigon->Next

Ta t password cho ti khon root, ti khon root l ti khon dng qun tr h thng v c quyn cao nht trong h thng.(bt buc phi 6 k t tr ln) tip ta chn Next.

y l phn ci t cc gi cho LinuxTa chn Customize now-> chn Next

Chn cc chng trnh v cc gi ci tChn nhm phn mm chnh bn tri->tip chn nhm phn mm con bn phi->chn optional gi hin thi5danh sch cc phn mm. Thc hin chn hoc b chn ci t hay g b cc phn mm.

Chn Close->chn Next

H thng sn sng ci t ta chn Next

Cc a yu cu ci chn Continue.

Chng trnh ang c ci t.

Trong qu trnh ci chng trnh s yu cu b tng a vo.

Ci t thnh cng ta khi ng li bng cch nhn Reboot

Khi ng u tin sau khi ci t

ang c cc dch v ca Centos

First boot wizard xut hin,ta chn Forward

Chn Firewall: Enabled, v chn cc dch v c php truy nhp qua Firewall, c th thm cc port khc nu cn->chn Forward.

Chn cu hnh SELinuxChn SELinux settins: Disable->chn Forward

Chn ngy gi h thngNu ta mun thi gian s c Synchronized vi mt remote time server->chn qua tab Network Time Protocol

Tip ta chn Forward

To mt ti khon thng xuyn s dng trn h thng khc vi ti khon Root.

H thng kim tra mch m thanh trn my PC->chn Forward

Chng trnh hi c mun ci thm phn mm t a khc khng->chn Finish->chn Yes

H thng s khi ng li v vo Centos

Nhp username l rootNhp password l root

vo Centos.

LAB 2: H thng tp tin th mc

Cc hng phn phi Linux hu nh thng nht vi nhau v tn cc th mc chun trn Linux. Trong th mc gc bao gi cng l /. Di th mc gc thng c mt s th mc quan trng nh sau:

u tin ta vo Computer

Vo Filesystem

Trong hnh trn s hin ra mt s tp tin th mc c bn trn Filesystem ca Centos: Bin,Sbin: Cha cc tp tin nh phn h tr cho vic boot v thc hin cc

lnh cn thit Boot: Cha Linux kernel, file nh h tr cho vic load h iu hnh Dev: Cha cc tp tin thit b (nh CDRom,HDD,FDD.) Etc: Cha cc tp tin cu hnh h thng Home: Cha cc home directory ca ngi dng, y l ni lu tr tt c

cc file d liu, nhng file cu hnh, thit lp, ty chnh ca ngi dng c k hiu bng ~.

Lib: Cha kernel module, v cc th vin chia s cho cc tp tin nh phn trong Bin v Sbin

Lost + found, media, misc: L nhng th mc rng l ni lu tr cho nhng thit b lu tr khc nh USB, CDRom. V phn mm Linux khi ci t khng c th mc chun no nh th mc Program File nh trong Window, thay vo tng phn ca chng s c lu tr nhng th mc khc nhau.

Mnt: Cha cc mount point ca cc thit b c mount vo trong h thng

Proc: Lu tr thng tin v kernel Root: Lu tr home dicrectory cho user root Tmp: Cha cc file tm Usr: Cha cc chng trnh c ci t Var: Cha cc log file, hng i cc chng trnh, mailbox ca user.

Mun xem danh sch cc tp tin ta dng lnh : lsXem danh sch cc tp tin trn ngi dng root

y l Roots home:

Vo Roots home ngoi Desktop

Mt s la chn thng dng vi lnh ls-L: Hn th danh sch tp tin (ch hin th tn)-l : Hin th danh sch tp tin (gm nhiu ct: filename,size,date,.-a: Lit k tt c cc tp tin, bao gm nhng tp tin n-R: Lit k tt cac3 cc tp tin k c cc tp tin bn trong th mc son.Khi nim tp tin trong Centos c chia lm 3 loi chnh:

Tp tin cha d liu bnh thng Tp tin th mc Tp tin thit b

Ngoi ra Centos cn dng cc Link v Pipe nh l cc tp tin c bit.Xem cu trc tp tin h thng:

i vi Centos khng c khi nim cc a. Ton b cc th mc v tp tin c gn ln v to thnh mt h thng tin thng nht bt u t gc /. ngha cc ct:

Ct u ch ra quyn truy cp tp tin.r: Ch loi tp tinw: Truy cp quyn cho tp tin ca ch s hu.- : Truy cp quyn cho cc thanh vin trong nhm

By gi ta to cy th mc nh sau:

Qun l v thao tc vi tp tin:To th mc: mkdir

Ta s thy xut hin trong

Lit k cc tp tin v th mc: ls hay llLit k th mc hdh va to:

Lit k th mc unix:

Lit k window:

To tp tin: c nhiu cch to tp tinTo tp tin hello.txt vi ni dung welcome to come me v t trong win98:

Chng minh:

Thm cu I need to meet you vo tp tin hello.txt

Chng minh:

Xem ni dung tp tin: c nhiu lnh xem ni dung tp tin nh: cat, more, less, tail,Xem ni dung tp tin hello.txt:

Sao chp:Sao chp tp tin hello.txt sang th mc trananh:

Chng minh:

Sao chp th mc window sang th mc trananh:

Chng minh:

Lit k th mc trananh:

Di chuyn:Di chuyn tp tin hello.txt trong th mc trananh sang th mc thichau

Di chuyn th mc window trong trananh sang th muc thichau

i tn:i tn th mc window trong th mc thichau thnh wins

Sao chp tp tin hello.txt trong thichau sang thu muc baongoc v i tn xinchao.doc

Xem ni dung tp tin xinchao.doc trong th mc unix/baongoc

Xa tp tin: rm

Xa tp tin hello.txt trong thichau

Nh nhn yes ng xaNu mun xa m khng cn hi th thm (-f)

Xa th mc rng: xa th mc win95 trong window

Vo th mc: cdDi chuyn vo th mc win98

Di chuyn ln 1 cp:

Di chuyn nhanh v root: cd/

Xem th mc hin hnh: pwd

Tm kim:Tm kim tp tin hello.txt:

Tm chui I need to meet you trong tap tin hello.txt

Nn/gii nn:Dng gzip/gunzip:

Nn tp tin xin hello.txt:

Gii nn:

Dng lnh tar:Nn tp tin hello.txt thnh tp tin c ui .tar

Kim tra:

Nn tp tin hello.txt thnh tp tin c ui .tar.gz

Kim tra:

Gii nn ui .tar

Gii nn ui .tar.gz

LAB 3: Ci t phn mm, tnh tin ch v cch dng

1/Trong phn ny ta tin hnh ci t font VNI v UNICODE , ci t b g SCIM . Qun l phn mm, tm hiu v s dng cc tin ch .

Mt gii php g ting vit gn y nht l scim. u tin ta ci scim vo[root@dhcppc2 ~]# yum install scim*Sau khi ci t ta vo system>preferrence>more preferrence>input method

Ta chn use custom input method>scim.Sau log out vo ta thy xut hin

Ta chn vietnameseTip theo ta nh lnh[root@dhcppc2 ~]# geditV g ting vit vo

Tip theo ci font th ta ti v b font VNI.ZIP v UNICODE.ZIP sau to th mc cha font v b vo th mc loi font tng ng[root@dhcppc2 ~]# mkdir /usr/share/fonts/vni[root@dhcppc2 ~]# mkdir /usr/share/fonts/unicodeSau gii nn cc font ny [root@dhcppc2 vni]# unzip VNI.zip[root@dhcppc2 unicode]# unzip Unicodeall.zip

Vo open office :Application>word processor

2/Tin ch th 2 ta nn dng trong linux l tin ch duyt th mc nh nc trn window th y l tin ch MC u tin ta ti tin ch ny v thng qua lnh: [root@dhcppc2 ~]# yum install mcS hin ra thng tin ci t ta nhn Y tin hnh ci t.

Khi ci xong khi ng MC cch nhn:[root@dhcppc2 ~]# mc

y l chng trnh MC. Chng trnh MC rt hu dung cho chng ta ci t my in, thit lp bc tng la .u tin ta g lnh:[root@dhcppc2 /]# setup

y s xut cho ta nhng dng hiu chnh v cu hnh my in, bc tng la, bn phm. V d nh ta hiu chnh bc tng la ta vo firewall configuration

Mt bc tng la bo v chng li s xm nhp mng tri php .Nu c kch hot s chn cc kt ni n. Nu b v hiu ha (disabled) th bc tng la s khng hot ng, y l iu khng nn. Ta vo customize xem thm thng tin tng la.

y s cho php hiu chnh tng la theo 2 cch:

Cho php lu lng truy cp t giao din mng no (Trusted Devices) Cho php mt s giao thc chy qua tng la trong Centos. (allow

incoming)

3/Tin ich theo di cc traffic no ang gi vo my ni b (Iptraf):y l tin ch theo di giao thng mng kim tra kt ni mng bn ngoi no ang xm nhp vo my tnh .Ta ci tin ch ny qua lnh[root@dhcppc2 ~]# yum install iptraf

Tng t ta chn y ci t ,sao khi ci t xong ta g lnh:[root@dhcppc2 ~]# iptraf

Nhn 1 phm bt k:

Xut hin menu thc hin cng vic theo di giao thng trong mng. v d ta chn IP traffic monitor, tip theo chn all interfaces

Xut hin mng hnh theo di giao thng trong mng nh trn s hin IP ca my ta l 192.168.1.1 chy trn cng 520. Chng hn ta vo google qua web fifox s thy cc cng c m v a ch Ip gi nhn ca tng my

Ta thy r Ip ca my ch google l 74.125.71.103 chy trn cng 80.

4/Tin ch theo di traffic mng (tcpdump):y l tin ch theo di giao thng trn mng c sn trn Centos cng th hin kh y thng tin giao thng mng[root@localhost ~]# tcpdump

5/Tin ch theo di gi tin mng (ethereal):y l tin ch theo di gi tin c chuyn qua li gia mng cc b v mng internetu tin ta phi ci t ng dng qua lnh:[root@localhost ~]# yum install ethereal

Nhn y tip tc, trong gi etheareal s c gi wireshark v th nu mun si wireshark ta phi ti thm gi wireshark-gnome bng lnh [root@dhcppc2 ~]# yum install wireshark-gnome. Khi ta vo applications-internet-wireshark network analyer.

Tip theo ta vo web g www.google.com sau m wireshark len chn . Sau chn nh hnh bn di

V y l hnh nh bt gi tin trn centos qua wireshark.

6/ Cng c qun l service trong mi trng ha:y l cng c kim tra dch v no ang chy trn Centos, vo system-administration-services

Nhng phn nh du cho ngha l c mc nh s c chy trn Centos khi khi ng chng trnh. Mun tt dch v no th ta chon dch v v nhn stop:

Cn nu mun chy li th ta nhn start

LAB 4: QUN TR NGI DNG

1/Xem thng tin ngi dng:1/Tp tin /etc/passwd: L c s d liu ti khon ngi dng trn Linux di

dng tp tin vn bn.Cu trc file /etc/passwd

1.Username: c s dng khi user login, khng nn cha cc k t in hoa trong username2.Password: Nu s dng shadow password th nn s dng du * hoc k t x3.User ID(UID): y l mt s nhn dang c gn cho mi user , h thng s dng UID hn l username lm vic vi user4.Gruop ID(GID): L mt con s ca Group u tin m user ny tham gia (thng tin cc Group c trong file/etc/Group)5.User ID Info(cn gi l GECOS):Trng ny khng quan trng lm, trng cng c v ch dng cho mu5ch ch khai bo thng tin v User nh: Fullname, s T,..6.Home directory: Phi l ng dn y ti th mc s lm th mc ch cho User, mc inh y s l working directory khi user login. Nu ch n mt th mc khng tn ti th h thng s t gn l th mc gc (/).7.Shell: ng dn y ti Login Shell(trn linux thng l bin/bash). Nu trng trng ny th Login Shell mc nh l /bin/sh. Nu ch ti mt File khng tn ti th User khng th Login vo h thng t console hoc qua SSH bng lnh login.

Xem file /etc/passwd: cat /etc/passwd:

[root@dhcppc3 ~]# cat /etc/passwdroot:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/nologinsync:x:5:0:sync:/sbin:/bin/syncshutdown:x:6:0:shutdown:/sbin:/sbin/shutdownhalt:x:7:0:halt:/sbin:/sbin/haltmail:x:8:12:mail:/var/spool/mail:/sbin/nologin

2/Ni lu tr mt khu c m ha:Dng lnh cat /etc/shadow[root@dhcppc3 ~]# cat /etc/shadowroot:$1$yC5I.ZOQ$Sqh9cMeP6VdiJqtf3nm1y1:14847:0:99999:7:::bin:*:14847:0:99999:7:::daemon:*:14847:0:99999:7:::adm:*:14847:0:99999:7:::lp:*:14847:0:99999:7:::3/Lu thng tin v cc nhm:

Dng lnh cat /etc/group[root@dhcppc3 ~]# cat /etc/grouproot:x:0:rootbin:x:1:root,bin,daemondaemon:x:2:root,bin,daemonsys:x:3:root,bin,admadm:x:4:root,adm,daemontty:x:5:disk:x:6:rootlp:x:7:daemon,lp

4/Qun l ngi dng:To ti khon ngi dng: man usaradd ( xem cch to ti khon)

V d to ngi dng tn anh:[root@dhcppc3 ~]# useradd anhKim tra anh trong /etc/passwd:

Kim tra anh trong /etc/shadow:

Kim tra anh trong /etc/group:

t pass cho anh:[root@dhcppc3 ~]# passwd anhChanging password for user anh.New UNIX password: BAD PASSWORD: it is WAY too shortRetype new UNIX password: passwd: all authentication tokens updated successfully.

Kim tra anh trong etc/shadow:

To ngi dng c home directory l th mc /tmp/anh v c dng m t xin cho anh1.[root@dhcppc3 ~]# useradd -c "xin chao anh1" -d /tmp/anh1 anh1

Kim tra user va to:[root@dhcppc3 ~]# cat /etc/passwd | grep anh

To anh2 c home directory l /tmp/anh2 v thuc group anh:[root@dhcppc3 ~]# useradd -d /tmp/anh2 -g anh anh2

Kim tra anh2 trong /etc/passwd:

Kim tra anh2 trong /etc/group:[root@dhcppc3 ~]# cat /etc/group | grep anhanh:x:500:anh1:x:501:

5/Thay i pass ca ngi dng:Thay i pass cho tai khon anh[root@dhcppc3 ~]# passwd anhChanging password for user anh.New UNIX password: BAD PASSWORD: it is WAY too shortRetype new UNIX password: passwd: all authentication tokens updated successfully.

Tng t thay i pass cho anh1, anh2

6/Thay i thng tin ngi dng:Dng cu lnh xem hng dn:

Thay i home directory ca anh1 l: /home/anh1:[root@dhcppc3 ~]# usermod -d /home/anh1 anh1

Kim tra anh1 trong /etc/passwd:

Thay anh1 thuc group anh:[root@dhcppc3 ~]# usermod -g users anh1

Kim tra anh1 trong /etc/passwd:

7/Kha v m kha ti khon ngi dng:Kha anh: passwd l anh (hay dng lnh usermod L anh)[root@dhcppc3 ~]# passwd -l anhLocking password for user anh.passwd: Success

Kim tra ngi dng trong /etc/shadow:

M kha anh : passwd u anh (hay dng lnh usermod U anh)[root@dhcppc3 ~]# passwd -u anhUnlocking password for user anh.passwd: Success.

Kim tra anh trong /etc/shadow:

8/To nhm ngi dng:Cch s dng : man groupadd

To nhm tn group1:[root@dhcppc3 ~]# groupadd group1

Kim tra nhm /etc/group:

9/Thay i thng tin nhm:Cch dng: man groupmod

Thay i tn group1 thnh nhm 1:[root@dhcppc3 ~]# groupmod -n nhom1 group1

Kim tra file /etc/group:

Thay i gid ca nhom1 thnh 600:[root@dhcppc3 ~]# groupmod -g 600 nhom1

Kim tra file /etc/group:

10/Xa nhm:Xa nhom1:[root@dhcppc3 ~]# groupdel nhom1

Xem file /etc/group:

11/ng nhp/Thot:ng nhp vo anh: su anh

Thot khi anh : exit

Xem ni dung tp tin etc/login.defs:[root@localhost ~]# cat /etc/login.defs | more

y l tp tin nh ngha cc chnh sch lin quan n password: di pass, ngy ht hn, ngy cnh bo..PASS_MAX_DAYS 99999PASS_MIN_DAYS 0PASS_MIN_LEN 5PASS_WARN_AGE 7

Tp tin ny cho php ta nh ngha khi to user mi, c to home directory khng?CREATE_HOME yes

Khi xa mt user, c xa lun group khng?. C xa c cc cron,job khng?USERDEL_CMD /usr/sbin/userdel_localUSERGROUPS_ENAB yesSa option CREATE_HOME , khng cho php to home directory:CREATE_HOME no

LAB 5: QUN L TIN TRNH

1/ Lit k cc tin trnh ang chy trn h thng:[root@dhcppc3 ~]# ps -ef | more

2/ Xem nhng ngi ng nhp vo h thng:[root@dhcppc3 ~]# who #root :0 2010-09-19 20:58root pts/1 2010-09-19 20:58 (:0.0)

3/Hin th ngi dng ng nhp vo h thng v nhng g h lm:[root@dhcppc3 ~]# w #

4/Cho thy tin trnh ang chy bi ngi dng:[root@dhcppc3 ~]# ps #

5/Hin th tt c qu trnh ngi dng Root:[root@dhcppc3 ~]# ps aux | grep root

6/Xem lng dng b nh v CPU:[root@dhcppc3 ~]# top #

7/Hy tin trnh ang chy:[root@dhcppc3 ~]# kill -9 44584458: l PID-9: l i s cn thm vo tt tin trnh

LAB 6: QUN L TI NGUYN CNG

1/Hin th khng gian a:[root@dhcppc3 ~]# df

Nhn vo ct Mount on ta thy c mt tp tin l l /dev/shm. y l mt tp tin quan trng gip ci thin hiu sut ca phn mm. xem ht chc nng ca df ta dng lnh:[root@dhcppc3 ~]# man df

2/Hin th khng gian a th mc hin ti:[root@dhcppc3 ~]# du -sh9.2M

3/Hin th khng gian a thc hin cc tp tin v th mc:[root@dhcppc3 ~]# du -sh *

4/Hin khng gian a th mc v tp tin khc nhau:[root@dhcppc3 ~]# du -s * | sort nr

Nu cn thm cch s dng c th du ta nhp lnh:[root@dhcppc3 ~]# man du

5/Mount trn centos:Trn h thng Linux cng nh centos, mt phn vng cn c muont trc khi s dng. Mt phn vng s c muont vo th mc v tt c d liu ghi vo th mc s c ghi ln phn vng mount. V d phn vng s 1 c mount ti /. Phn vng s 2 c mount ti /tmp. Nu ta khng muont phn vng s 2 ti /tmp m ghi d liu ln th d liu vn ch nm file s 1.

5.1/Mount v Umount CDRom:To th mc cdrom trong th mc /mnt:[root@dhcppc3 ~]# mkdir /mnt/cdrom

Thc hin lnh mount: mount /dev/cdrom /mnt/cdrom[root@dhcppc3 ~]# mount /dev/cdrom /mnt/cdrommount: block device /dev/cdrom is write-protected, mounting read-only

Kim tra th mc va mount:

Thc hin umount cdrom tt cd i:[root@dhcppc3 ~]# umount /mnt/cdrom

Xem li th mc mount: