Tom Tat Lenh Ubuntu

Ver 2.0 [QUN TR MNG LINUX: TM TT LNH LINUX SERVER]

Bin son: ThS u Bu Long-Khoa CNTT-Trng H S Phm TP. HCM Trang 1

CH : UBUNTU SERVER Tm tt l thuyt cc lnh qun tr h thng v mng

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MC LC I. Cc lnh shell c bn............................................................................................... 5

1. Cc lnh lin quan n vic ng nhp, ng xut, qun l tp tin, ngi dng, mt khu...................................................................................................................... 5

a. Cu trc cy th mc trong Ubuntu Linux. ...................................................... 5

b. Cc lnh qun l tp tin v th mc. ................................................................ 7

c. C ch phn quyn trn tp tin v th mc. ..................................................... 8

d. C ch qun l ngi dng v nhm. .............................................................. 9

e. C ch lu tr v qun l mt khu. .............................................................. 10

2. Cc lnh xem thng tin v ci t gi phn mm cho h thng. ....................... 11

a. Cc lnh xem thng tin v qun l cc tin trnh (process) ang chy trn h thng. ..................................................................................................................... 11

b. Ci t, g b v cp nht gi. ....................................................................... 12

c. Xem thng tin v phn cng, ghi nhn cc s kin trn h thng. ................ 13

d. Xem thng tin v dung lng a, dung lng th mc, ........................ 14

e. C ch pipeline trong lc thc thi lnh. ......................................................... 15

II. Cu hnh cc thit t ban u cho card mng v h thng mng trn client. ...... 16



1. Xem thng tin cu hnh hin ti ca card mng. ............................................... 16

2. Cu hnh IP tnh v ng cho card mng. .......................................................... 17

3. Cu hnh nh tuyn (routing). ........................................................................... 18

4. Gim st v qun l bng thng mng. .............................................................. 19

5. Cu hnh DNS trn client. .................................................................................. 21



GHI NH 1



GHI NH 2



I. Cc lnh shell c bn.

1. Cc lnh lin quan n vic ng nhp, ng xut, qun l tp tin, ngi dng, mt khu.

C rt nhiu l do chng ta tm hiu v c ch dng lnh trong Linux nh tng tc mt cch trc tip vi h thng, qun l cc ngun ti nguyn, g li trong khi pht trin phn mm hoc trin khai h thng mng Ubuntu cng nh cc h iu hnh da trn nhn Linux khc cung cp mt tp hp v cng a dng cc lnh t n gin n phc tp p ng nhu cu t ngi dng thng thng n nhng chuyn gia v h thng.

a. Cu trc cy th mc trong Ubuntu Linux.

Khng ging nh trong Windows, cy th mc trong Ubuntu bt u t mt im gc duy nht gi l th mc root, cc phn vng a cng c gn kt vo

mt th mc nhnh trn cy th mc ny mt cch t ng hoc th cng.

H thng tp tin trong Linux c phn bit ch hoa v ch thng, do cn ch khi t tn th mc, g lnh hoc truy cp vo th mc web trn server Linux.

Ch : Trong Linux, tt c mi ngun ti nguyn, ngoi tr cc tin trnh u c xem l tp tin. V d nh a, chut, bn phm T ta c cc loi tp tin khc nhau: tp thun vn bn, tp tin khi (i din cho cc thit b lu tr, truy xut theo block), tp tin thc thi Pht biu ny khng loi tr th mc, vn cng l mt loi tp tin cha tn v a ch truy xut n cc tp tin bn trong n. Cc loi tp tin khc nhau c vit tt nh bng k hiu sau:

File thng thng

Th mc Lin kt Thit b nhp k t

Socket mng Thit b lu tr

- d l c s b



/: Th mc gc, cha tt c cc th mc khc.

/home: Th mc nh l ni cha tt c cc thng tin, ti liu ca tng ngi dng, mi ngi dng (ngoi tr ngi dng root-l ngi dng c quyn qun tr ti cao) s c mt th mc con ring nm trong th mc /home ny.

/dev: Cha cc ng dn thit b phn cng nh cc a, phn vng, thit b nhp xut...

/etc: Cha cc file cu hnh cho h thng v cc dch v.

/etc/init.d: Cc script cn thit cho qu trnh khi ng h iu hnh Linux.



/usr/bin: Cha cc file thc thi thng thng.

/usr/sbin: Cha cc file thc thi dnh cho qun tr h thng.

/usr/share/doc: Cc loi ti liu khc nhau.

/usr/share/man: Hng dn s dng cho cc lnh.

/usr/src: Cha m ngun cho cc ng dng trong h thng (nu c)

/usr/src/linux: Cha m ngun cho nhn (kernel) ca Linux

/bin: Cha cc file thc thi trc v khi khi ng.

/tmp, /var/tmp: Cha cc file tm.

/var: Cha cc file cu hnh v d liu ca cc dch v.

/var/log: Cc file log ghi nhn li cc s kin v li trn h thng.

/lib: Th vin lin kt ng (th vin chia s).

/proc: Cha cc thng tin v cc vng b nh phc v cho cc tin trnh ang thc thi.

b. Cc lnh qun l tp tin v th mc. - To th mc:

mkdirTnthmccnto

- Xa th mc:

rmdirTnthmccnxa

- Di chuyn, i tn th mc hoc file:

mvNgunch

- Sao chp file hay th mc:

cpNgunch

- To file text:



cat > Tnfilecnto Sau g ni dung ca file vo, n Ctrl+D kt thc.

- Xem ni dung file text:

catTnfilecnxem

- Xa file:

rmTnfilecnxa

- Lit k danh sch file v th mc:

lsTnthmc

Dng vi tham s l hin th chi tit hn: ls----llllTnthmc

- c x dng u ca file text:

headnxTnfilecnc

- c x dng cui file text:

tailnx Tnfilecnc

c. C ch phn quyn trn tp tin v th mc.

Xt trn bt k h iu hnh no th vic phn quyn c ghi file quyt nh tnh an ton trong thao tc lu tr. Do , quyn hn khi thao tc trn file v th mc

rt c Linux ch trng.

C 3 ch th trong c ch phn quyn: User-dng cp quyn cho ngi dng s hu file, Group-cp quyn cho nhm s hu file, Other-cp quyn cho nhng ngi cn li.

Mi ch th s c 3 quyn hn khc nhau l: Read (r: quyn c), Write (w: quyn ghi) v Execute (x: Quyn thc thi file).

Quy c v quyn hn: Read=4, Write=2, Execute=1. Quyn hn tng hp cho mt i tng (User, Group hay Other) c tnh l tng ca 3 s trn. Nh vy c th thy Linux biu din quyn hn bng mt con s nguyn 3 bits.



V d: 755 c ngha l: User: 7=4+2+1(Read, Write, Execute), Group: 5=4+1 (Read+Execute), Other: 5=4+1 (Read+Execute).

- Lnh dng thay i quyn hn p dng cho file hay th mc:

chmodxyzTnFileCnCpQuyn

Vi x: Quyn cho User, y: Quyn cho Group, z: Quyn cho Other

V d: chmod755/home/john/mydata.txt

d. C ch qun l ngi dng v nhm.

Mi ngi dng s c th thuc v mt hay nhiu nhm, trong c mt nhm

chnh (Initial Group).

Ngi dng c quyn hn ti cao trong h thng l ngi dng root, tng t

ta c nhm root. Trong ch dng lnh ta c th bit c ngi dng hin ti c phi l root hay khng bng cch quan st du nhc lnh: Du nhc l $: ngi dng thng thng; du nhc l #: ngi dng l root.

Nhm chnh l nhm bt buc phi c ca mi ngi dng.

Khi mt ngi dng to ra mt file th mc nh ngi dng y s s hu file

, nhm chnh ca ngi dng s l nhm s hu file y.



Mt nhm c th cha nhiu ngi dng khc nhau, nhm c dng n gin ha vic cp quyn. V d: Nu mun cho php ngi dng s dng mt ti

nguyn no , ta ch vic thm ngi dng vo nhm tng ng c cp quyn.

Mi ngi dng v mi nhm u c mt s nh danh gi l UserID v

GroupID.

- Lnh to Group:

groupaddTnNhm

- Lnh xa Group:

groupdelTnNhm

- Lnh to User:

useradd[-cch thch][-dthmchome] [-gNhmchnh][-Gnhm[,...]]TnUser

- Lnh xa User:

userdelTnUser

Ch : Trong linux ta c th xem phn hng dn s dng ca hu ht cc lnh bng cch g mantnlnh, hay infotnlnh

e. C ch lu tr v qun l mt khu. Mt khu ca user c lu dng m ha, mc nh mt khu c lu trong

file /etc/shadow

Thng tin v ti khon ca cc user c lu trong cc file: /etc/passwd, /etc/shadow

Thng tin v nhm c lu trong cc file: /etc/group, /etc/gshadow

- Lnh dng thay i password cho mt user no :

passwdTnUser



H thng s yu cu nhp password mi cho user ny, cn c quyn root

thc hin thao tc ny.

2. Cc lnh xem thng tin v ci t gi phn mm cho h thng.

a. Cc lnh xem thng tin v qun l cc tin trnh (process) ang chy trn

h thng.

Mi tin trnh ang chy trong h thng c nh danh bng mt ProcessID,

tin trnh c mt u tin, gi l Process Priority.

Trong ng cnh tin trnh th nht gi thc thi tin trnh th hai, ta gi tin

trnh th nht l tin trnh cha, tin trnh th hai l tin trnh con.

xem thng tin v cc tin trnh ang chy, dung lng b nh v ti nguyn

x l ang cp cho tin trnh ta c th dng lnh top

xem c cy cc tin trnh ta dng lnh pstree



kt thc mt tin trnh ang thc thi ta c th dng lnh kill hoc killall

killIdcaprocesscntt

killallTncaprocesscntt

Trong v d v lnh top trn, ta c th kt thc tin trnh top bng 2 cch: kill

5763 hoc killall top

b. Ci t, g b v cp nht gi.

Bn cnh cng c trong giao din ha (GNOME, KDE...) ci t phn mm cho Linux, cc lnh ci t bng dng lnh l khng th thiu i vi ngi

qun tr h thng.

Mi bn phn phi linux c h thng qun l gi khc nhau. Trong Ubuntu

Server l b cng c apt-get.

Lnh apt-get dng mt kho lu tr trn mng internet hoc trn a ly cc

gi ng dng v v ci t.

Danh sch a ch cc kho lu tr phn mm c t trong file

/etc/apt/sources.list

Bn cnh , b apt-get cn lm cc cng vic qun l ci t trn my cc b.



- cp nht danh sch gi phn mm trn my cc b vi kho lu tr ta

dng lnh

apt-getupdate

- nng cp tt c cc gi phn mm ang chy trn h thng theo phin

bn mi nht c trn kho lu tr ta dng lnh:

apt-getupgrade

- ci t mt gi phn mm no ta dng lnh:

apt-getinstalltngicnci

Tn gi cn ci phi tn ti trong danh sch gi.

- g b mt gi phn mm khi h thng ta duung lnh:

apt-getremovetngicng

c. Xem thng tin v phn cng, ghi nhn cc s kin trn h thng.

Xem thng tin chi tit v phn cng ta c th dng lnh lspci

Xem thng tin v cc thit b kt ni thng qua cng usb: lsusb



Lnh lshw dng xem thng tin chi tit v cc thit b, ngt, cc tuyn bus

ca h thng.

Cc file log trong h thng c lu tr trong /var/log, trong c cc file chnh l syslog: ghi nhn li cc s kin ca h thng, dmesg: cc thng tin v qu

trnh khi ng ca h thng. Ngoi ra cn rt nhiu file log ng vi cc dch v ang

chy nh apache, mysql

Ta c th dng lnh tail xem phn cui ca file log, v d: xem 15 dng

cui trong file syslog: tailn15/var/log/syslog

d. Xem thng tin v dung lng a, dung lng th mc,

Xem thng tin v dung lng cc phn vng ang c s dng: dfh

- Xem thng tin v tng dung lng ca tng th mc con trong mt th

mc no :

dushngdn



e. C ch pipeline trong lc thc thi lnh. C cu pipeline trong linux p ng cho nhu cu ly kt qu ca mt lnh

truyn vo lnh khc, v trong thc t ngi qun tr vin c th phi thc hin nhiu

thao tc phc tp lin quan n nhiu yu cu nh: thng k cc t tn cng t bn ngoi, qun l ti nguyn lu tr trn mt lng ln ngi dng, sn lc cc nguyn nhn gy li cc cng vic ny i hi phi kt hp nhiu lnh li vi nhau v cc

lnh c th ly kt qu ln nhau thc thi.

Cu trc tng qut:

Lnh_1 | Lnh_2 ...

Khi s dng nh trn, Lnh 2 s ly tham s u vo l kt qu ca lnh 1,

tng qut ta s c lnh sau ly tham s u vo t kt qu ca lnh trc.

V d: ls /etc/init.d | tail n 5 Lnh ls /etc/init.d s tr v kt qu l danh sch cc file hay th mc c trong

/etc/init.d, tuy nhin kt qu ny khng hin ra mn hnh, m c dn vo cho lnh tail hin ra 5 dng cui. Kt qu ca lnh nh sau:



II. Cu hnh cc thit t ban u cho card mng v h thng

mng trn client.

1. Xem thng tin cu hnh hin ti ca card mng.

Tng t nh trong Windows, Ubuntu Linux cng c cc lnh xem v cu

hnh cho cc card mng trong h thng.

- Lnh xem thng tin ca cc card mng ang hot ng:

ifconfig[tncardmng]

Tn ca cc card mng c t ng t theo quy c ca Linux, vi card

mng Ethernet: eth0, eth1...

Cc thng tin hin ra bao gm: IP, broadcast, netmask, MAC, dung lng gi,

dung lng nhn...

Lnh ifconfig khng c tham s s xut ra thng tin cu hnh cu tt c cc

card mng.



2. Cu hnh IP tnh v ng cho card mng.

Cc thng tin cu hnh cho card mng c lu trong file

/etc/network/interfaces

Cu hnh IP ng da trn giao thc DHCP, ta thm vo file cu hnh trn cc

dng sau (gi s ang cu hnh cho card mng eth1):

auto eth1

iface eth1 inet dhcp

Dng u tin dng t ng bt card mng eth1 khi khi ng Linux hoc

khi c tn hiu. Dng th 2 cho h thng bit dng a ch ng vi giao thc

DHCP.

Cu hnh IP tnh: Xt v d cu hnh tnh cho card mng eth0 vi cc thng

tin: IP 192.168.1.2, subnetmask 255.255.255.0, a ch default gateway 192.168.1.1 ta

thm vo file /etc/network/interface nhng dng sau

auto eth0 iface eth0 inet static address 192.168.1.2 netmask 255.255.255.0 gateway 192.168.1.1



Ch : sau khi cu hnh thng qua cc file cu hnh, p dng thit t mi ta

chy lnh /etc/init.d/networking restart khi ng li dch v mng theo cu hnh mi.

3. Cu hnh nh tuyn (routing). Cc ty chn v routing gip cho mng hot ng n nh hn, linux cung cp

lnh thao tc trn bng nh tuyn (routing table). Thao tc nh tuyn c bit hu dng khi my c nhiu card mng ni vi nhiu mng khc nhau. Cc thao tc bao

gm: xem thng tin nh tuyn, thm mt default gateway, thm mt dng nh tuyn

mi, xa mt dng nh tuyn...

xem thng tin ta dng lnh route, lnh ny s hin th thng tin v bng

nh tuyn, dng c destination l default chnh l dng m t v default gateway.

- thm mt default gateway ta dng lnh route vi c php:

routeadddefaultgwachIPgateway

V d thm mt default gateway c a ch 192.168.100.2 vo bng nh

tuyn ta chy lnh routeadddefaultgw192.168.100.2, sau khi thm ta c

th gi lnh route kim tra.

- xa mt default gateway ta dng lnh:

routedeldefaultgwachIPgatewaycnxa

Thm mt mu tin nh tuyn: Xt 2 v d sau



routeadd192.168.1.8gw192.168.10.1

routeaddnet192.168.100.0

netmask255.255.255.0gw192.168.10.1

Lnh th nht dng thm mt ng nh tuyn n host c IP 192.168.1.8 thng qua gateway l 192.168.10.1

Lnh th hai dng thm mt ng nh tuyn n mng c ip

192.168.100.0/24 thng qua gateway l 192.168.10.1

Xa mt mu tin nh tuyn: Tng t nh lnh route add nhng thay th bng

route del

Ch : Khi nh tuyn cho ng i n mng ta cn ch nh netmask. C th thm ty chn dev ch ra tn card mng no c dng cho mu tin nh tuyn

c thm.

4. Gim st v qun l bng thng mng. Linux cung cp rt nhiu cng c, gip cho vic qun l mng t hiu nng

cao. Cc cng c ny c thit k giao tip vi nhn linux v gim st/can thip

vo qu trnh x l gi tin.

Mt s cng c gim st v qun l bng thng mng: iftop, bwm-ng, bwm, wondershaper

Cng c iftop: dng gim st bng thng mng theo tng kt ni trn mt card mng nht nh. Cch dng:

iftopiTnCardMng



Cng c bwm-ng, bwm: Dng gim st bng thng gi (Tx) v nhn (Rx) trn tt c cc card mng, n v hin th l Kilobyte/s. Cch dng:

Gi lnh bwm-ng

Cng c wondershaper: l cng c dng gii hn bng thng trn mt card mng no , cch s dng:

wondershapertncardmng tcdowntcup

Tc down v up tnh bng Kilobit/giy

Ch : khi va ci t h thng, mc nh mt s gi cng c trn cha c

ci. ci ta dng lnh apt-getinstalltn_gi.



5. Cu hnh DNS trn client.

Vic cu hnh DNS trn my client n gin ch l vic ch ra IP ca DNS

server cn dng khi truy vn.

Tp tin cha thng tin DNS trn client l /etc/resolv.conf

thm mt DNS server vo danh sch ta thm mt dng c dng

nameserverIPDNSserver vo file trn.

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Tom Tat Lenh Ubuntu