Linux

RHEL Linux basic commands cat bzip gzip pwd cd mkdir

In our last assignment you perform some basic task related to system administration from normal user. In this assignment we will extend this further. To complete this assignment login form our normal user Vinita.

How to redirect the matter of files in a new file

Create two file and write some text in them.


$cat > one
This is first file
$cat > second
This is second file

Now we will combine these two files in a single file. In standard linux its call redirection of output.


$cat one second > new
$cat new
This is first file
This is second files

Then what exactly this command did? As you know cat command is used to display the matter of file so it will first display the matter of first file and then it will display the matter of second file. But as you put a > sign at the end of command so despite of showing this output on screen command will redirect this matter to a file.

How to execute multiple commands in a single row


$[command] ; [command] ; [command] ;[command]……..

To execute multiple commands from single row use a ; between them form example


$cat new ; mkdir xyz ; mkdir rat ; ls
This is first file
This is second files
new xyz rat

this command will first execute the first command which is cat new so it will display the matter of new file, further is mkdir xyz so it will create a xyz directory , further is mkdir rat so will create a rat directory and in the end we use ls command so it will list the contain of current directory.

How to create multiple sub directory form single command

To create multiple sub directory from a single command use –p switch with mkdir command for example


$mkdir –p a/b/c/d/f/g/h/i/j

In this example we created 9 subdirectories form a single mkdir command. Now verify it by listing.


$ls
new  xyz rat a

now change the directory to verify the depth of directories.


$cd a/b/c/d/f/g/h/i/j
$pwd
/home/vinita/a/b/c/d/f/g/h/i/j

Come back to home directory. Simple cd command without passing any argument will do this.

$cd

How to move multiple file in directory with a single commands?

Give all files name one by one with a single space between them and in the end give the destination directory name for example
$mv new first second xyz

This command will move three files new, one, second to the xyz directory.


$cd xyz
$ls
New one second
$cd ..

how to take back-up and restore files and directories.

tar command is used to take the back up with –cvf switches and the same tar command is used to restore the matter with –xvf switches. For example


$tar –cvf backup.tar xyz
$ls
$rm –rf xyz

In linux you cannot restore the data once deleted unless you have backup. Now restore these files and directory.


$tar –xvf backup.tar
$ls
$cd xyz
$ls
new first second
$cd ..

How to compress files to save disk space?

Create a large file and check how much disk space is consumed by this file


$man ls > manoj
$du –h manoj
12k manoj

File manoj is using 12k space on hard disk. For exam prospective you should familiar with two compress utilities.


$bzip2 [file name]                      {command syntax}
$bzip2 manoj
$ls
$du -h  manoj.bz2
4k manoj.bz2

To decompress file
$bzip2 –d manoj.bz2 $ls manoj as you can show file has been decompressed. Now use other utility to compress the file.


$gzip manoj
$ls
manoj.gz
$du –h manoj.gz
4k manoj.gz
$gzip –d manoj.gz
$ls
manoj

basic network configurations ip, hosts file, portmap and xinetd services

In this article we will discuss all those necessary steps which you need to perform before solving networking related questions in RHCE exam. Don't skip this tutorial, giving few minutes to this could save you from huge problems in exam. All steps are given in a sequences don't skip them whether you them or not.

Check LAN card driver is installed or not.

LAN driver is the top most part for network. To check it run setup command

Select network configuration from list

If you see LAN card here mean you have LAN driver
select lan card

if you don't see here anything and Linux drop you back on list manu means you don't have LAN driver. Install is first.

If you don't know how to install LAN driver then follow this link.Installing lan card driver, location of important networking files and descriptions

Check proper IP configuration

All systems on RHCE exam should have an properly configured IP address. During this entire practical we are using three systems. There description is given below Check these systems for properly configured IP address. you can review our pervious article if you feel trouble in IP configuration.Network configuration commands ip ifconfig ping netstat arp mii-tool

Node	Operating system	Name	IP
PC1	Linux RHEL	Server	192.168.0.254
PC2	Linux RHEL	Client1	192.168.0.1
PC3	Windows XP	Client2	192.168.0.2

Change host name

If you have skipped hostname during installation then it would be localhost.localdomain. You can change hostname with hostname command but this change would be temporary. To change hostname permanently do editing in /etc/sysconfig/network.
set computer name as shown in table.

#vi /etc/sysconfig/network

On server system set it to Server and in client system set it Client1

Check /etc/hosts files for name resolution

Several Linux server depend name resolution. This file should have entry of all network systems. It will save you from naming related problem. In our network it should look like this on both Linux system Server and Client1

Check firewall status

Firewall is the necessary security part of Linux system which is connected to Internet. But in exam we are not going to use Internet so it’s good practice to disable it.

To disable firewall run setup commands

Now select firewall configuration from list and click on run tool

Select disable and click on ok and quit to return on command prompt.

System reboot require to take effect so reboot system with reboot -f commands

Check portmap and xinetd package status

Almost every Linux server needs these two rpm to function properly. First check that these rpm are install or not. If no rpm is install then install them via rpm commands. If you don't know how to install rpm then follow this link.Linux RPM Red Hat's Package Manager

If you have rpm then check there status via setup commands

Now select system service from menu put a star in front the portmap service Now put star in front the xinetd service Click on ok and select quit to come back on command prompt

Now restart these two service. To keep on these services after reboot on then via chkconfig command After reboot verify their status. It must be in running condition

Linux Install Requirements:

· / = 25000 · /Boot = 500 · Swab = 4000 · /Usr = 6000 · /Home = 10000 · /Var = 10000 FILE SYSTEM: · / = Root · /Bin = Binary File for User · /Sbin = Binary File for Administrator · /proc = Processing Status of System · /Usr = User Level Application · /Var = Variable Information · /tmp = Temporary file of Directory · /Opt = Optional Dir Company · /Mnt = Mount of Unmount the file Dir · /Media = Removable Media · /dev = Devk (or) Driver files · /lib = Library file · /etc = Configuration file [Root@localhost ~]# (or) $ Root = Currently Login User Name Localhost = Computer Name ~ = User Home Directory # = Represent as Administrator $ = User Shell Shutdown Command · Shutdown -h Now = Immediate Shutdown · Shutdown -h 20:00 = Pc at 8.00 PM Shutdown · Shutdown -h +20 = Pc in 20Min Shutdown Restart Command · Shutdown -r Now = Immediate Shutdown · Shutdown -r 20:00 = Pc at 8.00 PM Shutdown · Shutdown -r +20 = Pc in 20Min Shutdown Cancel Shutdown · Shutdown –c File Create · Cat > filename eg:-Cat>kalai Directory Create · Mkdir - Directory Name eg:-Mkdirkalai CD Drive Open · mount /dev/cdrom /mnt · Cd /mnt Eject · Cd\ · Umount /mnt · Eject Install Software · rpm -ivh telnet-9.3.3 User Add with Password Useraddkalai Passwd kalai = to create a user User Add without Password Useraddkalai Passwd -d kalai = to create a without Password User Remove Userdel -r kalai = to remove user Password change Passwd kalai = change Password Move 1. Cat mano>>kalai = to move all data to another file (kalai) without delete. 2. Cat mano>kalai = to move all data to a new file (kalai) with delete. 3. Cat manokalai>kutty = to move 2 file another file (kutty). 4. Cat kalai = view file 5. Vi kalai = view & edit 6. Cat > .mano = Create hidden files 7. Ls –d = view hidden files 8. Cat .mano = to view hidden files 9. Mkdir .mano = to create a hidden Dir 10. Cd .mano = to view hidden Dir 11. Cp = Copy 12. Cp kalaimano = to copy file(kalai to mano) 13. Cp –r kalaimano = copy to mano remove kalai data. 14. Ls = view all files 15. Pwd = present working Dir. 16. Alias = to view alias 17. Alias c=clear = create a shortcut clear alias. 18. BC = Binary calculator. 19. Gzipkalai = to zip file (kalai) 20. Gunzipkalai = to unzip file (kalai) 21. Cat kalaigz = to view zip file (kalai) 22. Neat = open network windows 23. Help = Show all comment 24. Ps -ax = to view Process ID. 25. Kill -9 = kill Process ID. 26. Cal = calendar 27. Cal 2010 = view 2010 calendar 28. Cal 9 1986 = view month in year. 29. Wall = all user 30. Write (user) = sent message admin user. 31. Ls |less = view page to page. 32. :q! = without save 33. :wq! = with save 34. :w! = save without exit 35. Setup = comment view setup. 36. Ifconfig = view IP Address. 37. History = to view all usage comment 38. History –c = to clear all comment 39. Rpm –qa = software check 40. Chmod = file permission 41. Rm –rf = remove files ===================================================================== INTRO -KERNEL - CORE OS (OPERATING SYSTEM) IT CONTROL THE HARDWARE ------------------------------------------------------------------- Linux History 1970: UNIX very popular 1984: Richard Stallman /dev/fd0 : /dev/fd1 /dev/cdrom /dev/cdrecorder cdwriter /dev/dvdreader /dev tape drive /dev/mt0 ---------------------------------------------------------------------- KERNEL CORE OS MAJOR VERSION 1.0 2.0 MINOR VERSION .6 .18 BUG VERSION (RELEASE) - FIX(PATCH) ------------------------------------- ODD NUMBER KERNEL 1.1 1.3 1.5--------2.1 2.3 2.5 2.7 EVEN NUMBER KERNEL 1.0 1.2 1.4 --------2.2 2.4 2.6 2.8 LINK IN LINUX Soft link Hard link More than one user working on single file, but diff link name SOFTLINK: If source file is deleted, destination file will not be reachable #ln -s sfile1 dfile1 HARD LINK: If source file is deleted, destinati0n file will be access #ln sfile2 dfile2 NOTE: If source/destination file modified, both file will be updated #ln (command for create a link) -------------------------------------------------- REDIRECTION OPERATOR IN LINUX > : write the output to file (If file is already existed it deletes the file and always create one) >> : append your data (If file is already existed it update the file) 1> : write the success message 2> :write the error messages UNDERSTANDING THE TYPES - : it refers the file l: it refer the link d: it refer the director c: character device s:network related b: block device --------------------------------------- copy : copy a file (cp): it refer the file l : it refer the link d : it refer the director c :character device s:network related b : block device Move/rename a file (mv) cut delimiter ------------------------------------------------ # cut -d: -f1 /etc/passwd | less [root@client1 covai]# cut -d: -f1 /etc/passwd | less ---------------------------------------------------- Run More Than One Command In A Single Line ls ; dir; cd /tmp; touch file10 How To Recover The Root Password Forgot the Root 1. ctrl+alt+del 2. once the boot screen display press esc press e edit 3. select the line no 2 & press e 4. linux single <press enter> 5. b (boot) start the pc with single user mode 6. without username/password it login as a root user 7. #passwd or #passwd root 8. reboot init 3 ------------------------------------------------------------------- PROCESS IN LINUX #ps -A | less What is the first process in Linux? init pid : process id teleterminal type cmd #pstree | less HOW TO START THE BACKGROUP PROCESS #startx& #xeyes& KILL THE PROCESS ------------------ #kill #gnome-system-monitor #top ------------------------------------------------------------- CHANGE/SET THE PRIORITY OF THE PROCESS --------------------------------------- 1. start the process with priority (nice ) 2. change the priority of the running process (renice) Range -20 to +19 (Highest) (Lowest) Root --------------------------------------------------------------- HISTORY FOR ROOT USER FOR NORMAL USER $echo $HISTSIZE #cd /home/kalai #vi .bash_profile ------------------------------------------------------------- Diff betweeninit 5 startx NOTES: COMMAND --------------- #env | less #gnome-system-monitor & #nice -n +15 xeyes& #renice -n -15 2778 #echo $HISTSIZE #jobs #ps -a | less #kill 2547 #ps -a #ps -a #pstree -i #chkconfig --list level 3 #chkconfig --list --levels 3 | less #chkconfig --list --levels 35 Package Installation · .exe/.dll not supported · .rpm ( RedHat package manager)[open source] - method Install/unistall/update EL5: Server EL6: Package · .bin (binary executable format) · .dpkg --------------------------------------------------------------- rpmMethod Of Installation (Text) -q : query -a : all packages -i : install -e :erase -U : upgrade -v : verbose : it show the output in the console/terminal -f : force -h : hash symbol DrawBack: must install the dependencies before install the main package ------------------------------------------------------------------ YUM :Yellowdog Update Modified It automatically installs the dependencies. ------------------------------------------------------------------ RPM PRACTICAL how to verify list of packages installed in my system? rpm -qa | less find the particular installed or not? rpm -qa | grep nfs how to install rpm -ivh<packagename> how to uninstall rpm -ef<packagename> without extension -------------------------------------------------------------------- Yum: It is a client/server arch model DUMP Need to be store in any one pc in the network, Yum server configuration 1. #rpm -ivhcreaterepo 2. verify the pack installed or not #rpm -qa | grep createrepo 3. create repository [Storage area: it refer where the installation files are located] #createrepo /backup/redhatdvd #yum remove xsane* #yum install -y xsane* - without confrom ----------------------------------------------------------------- YUM CLIENT CONFIGURATION ------------------------ #cd /etc/yum.repos.d #virhel-debuginfo.repo rhel-debuginfo-beta] name=Red Hat Enterprise Linux $releasever Beta - $basearch - Debug baseurl=http//redhat.com enabled=0 gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-beta-2 (change) rhel-debuginfo-beta] name=Red Hat Enterprise Linux $releasever Beta - $basearch - Debug baseurl=file:///backup/redhatdvd enabled=1 gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-beta-2 #yum clean all #yum list all baseurl=http://192.168.1.101/backup/redahtdvd ftp nfs //: network ///: local file ---------------------------------------------------------------- tar : tape archieve -c : create -v : verbose -f : file -x : extract gzip: 1. #gunzip test.tar.gz #tar -xvf test.tar (or) 2. #tar zxvf test.tar.gz winzip : ark -------------------------------------------------------- #./FILE #./configure system-config-packages REGULAR EXPRESSION IN LINUX ^ (CARET) : the line start with the character $ (dollar) : the line end with the character [ab] : set operator (a or b) [a-z] : set operator (from a-z) [A-Z] [a-zA-Z] [0-9] : set operator ( from o to 9 number) [root@server1 covai]# grep "red" file1 Red [root@server1 covai]# grep "^r" file1 red rvd rcd rkd [root@server1 covai]# grep "e$" file1 this is sample blue orange purchase [root@server1 covai]# touch file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: root # group: root user::rw- group::-w- other::-w- [root@server1 covai]# chown vik1 file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: root user::rw- group::-w- other::-w- [root@server1 covai]# chown vik1:purchase file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: purchase user::rw- group::-w- other::-w- [root@server1 covai]# chown :sales file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: sales user::rw- group::-w- other::-w- [root@server1 covai]# orange sales purchase admin rvd rcd rkd data1 data2 [root@server1 covai]# grep "r[vck]d" file1 rvd rcd rkd [root@server1 covai]# grep "[a-z]" file1 this is sample red green blue orange sales purchase admin rvd rcd rkd data1 data2 [root@server1 covai]# grep "r[a-z]d" file1 red rvd rcd rkd [root@server1 covai]# grep "data[012]" file1 data1 data2 [root@server1 covai]# grep "data[0-9]" file1 data1 data2 data3 ---------------------------------------------------------------------- File: it show the type of the file #file file1 [root@server1 covai]# file file1 file1: ASCII text ---------------------------------------------------------------------- UMASK VALUE IN LINUX --------------------- Root User when i create file in linux default permission by system : 644 when i create dir in linux default permission by system :755 what is the umask value in root user ? : 022 Normal User When i create file in linux default permission by system : 664 When i create dir in linux default permission by system:775 What is the umask value in NORMAL user? : 002 How the permission will be implemented? LINUX DEFAULT PERMISSION FILE 666 DIR 777 ROOT USER FILE CREAATE 666 - 022 ----- 644 ----- DIR CREATE 777 022 --- 755 --- How to change the umask? 1) Temporary #umask 055 666 055 2) Permanently change #cd /root #vi .bash_profile umask 055 #cd ~ [ go the the user home] #ls -a [ it show the hidden file ----------------------------------------------------------------------LINUX PERMISSION 1. chomod 2. setfacl/getfacl setfacl :acces control list getfacl : access #groupadd purchase [root@server1 covai]# setfacl -m u:vik1:rwx file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: root # group: root user::rw- user:vik1:rwx group::r-- mask::rwx other::r-- [root@server1 covai]# setfacl -x u:vik1:rwx file1 setfacl: Option -x: Invalid argument near character 8 [root@server1 covai]# setfacl -x u:vik1 file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: root # group: root user::rw- group::r-- mask::r-- other::r--[root@server1 covai]# touch file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: root # group: root user::rw- group::-w- other::-w- [root@server1 covai]# chown vik1 file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: root user::rw- group::-w- other::-w- [root@server1 covai]# chown vik1:purchase file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: purchase user::rw- group::-w- other::-w- [root@server1 covai]# chown :sales file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: sales user::rw- group::-w- other::-w- [root@server1 covai]# CHANGE THE OWNER OF THE FILE owner group owner:group [root@server1 covai]# touch file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: root # group: root user::rw- group::-w- other::-w- [root@server1 covai]# chown vik1 file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: root user::rw- group::-w- other::-w- [root@server1 covai]# chown vik1:purchase file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: purchase user::rw- group::-w- other::-w- [root@server1 covai]# chown :sales file1 [root@server1 covai]# getfacl file1 # file: file1 # owner: vik1 # group: sales user::rw- group::-w- other::-w- ---------------------------------------------------------------------- wc :wordcount ---------------------------------------------------------------------- working on grub.conf or menu.lst /boot/grub grub.conf menu.lst ---------------------------------------------------------------------- welcome message motd : message of the data #cd /etc #vimotd ---------------------------------------------------------------------- shell in linux shell : is an interpreter between user and the kernel $ cd /home ls user------->appln------------>shell----------->kernel------------>h/w #cat /etc/shells #finger rajan #chsh ---------------------------------------------------------------------- echo : print command create dir with subdir? mkdir -p rspuram/covai DHCP :DYNAMIC HOST CONFIGURATION PROTOCOL · It provide automatic ip to the client ip · we create a range of ip for number of client based on requirement. PRACTICAL 1[provide dynamic ip] PRACTICAL 2: [fixed dynamic address][mac/hardware/physical address DHCP SERVERCONFIGURATION [ 67/69] 1) #rpm -qa | grep dhcp 2) #yum install dhcp 3) #cd /etc/dhcpd 4) #vi dhcpd.conf [ /usr/share/doc/dhcp/ [sample file] 5) #service dhcpd restart 6) #chkconfig dhcpd on VERIFY THE LEASES Fromserver , u can verify which ip assigned to which client #dhcp.leass SAMBA: File Server · It is a protocol, share the files between windows and linux · port number 137 · smb : session message block Practical 1: View the Linux files from windows Practical 2: View the windows files from Linux Practical 1: Samba Server Configuration A) TEXT MODE B) #system-config-samba C) webmin # rpm -qa | grep samba # Yum install samba #cd /etc/samba/ #cp smb.conf smbcpy.conf #vi smb.conf Workgroup =<windows workgroup name> Security = share [Covai] Path = /tmp/covai #testparm[itverifies the confismbclient -L 192.168.1.103 -U Administrator guration file syntax error] #service smb restart [el6] #service smb restart [el5] #server nmb restart #chkconfig smb on #chkconfig nmb on Verify the share is working or not in win pc Double click the network--> it show linux pc name , if u dblclick it show the shared folder [root@server1 samba]# setup [root@server1 samba]# getsebool -a | grep samba samba_create_home_dirs --> on samba_domain_controller --> off samba_enable_home_dirs --> on samba_export_all_ro --> on samba_export_all_rw --> on samba_run_unconfined --> off samba_share_fusefs --> off samba_share_nfs --> on use_samba_home_dirs --> off virt_use_samba --> off [root@server1 samba]# setsebool -a samba_create_home_dirs=on Practical 2: In Windows PC (F:\mydata ) shared How to access from lin pc #smbclient -L 192.168.1.102 [ it show the shares from windows] #mount //192.168.1.102/mydata /mnt Convert The Linux User As Samba User #smbpasswd -a vik #smbpasswd -a raj smb.conf 101 : security = user [covai] 291 path = /tmp/covai 292 valid users = vik raj 293 browseable = yes 294 writable = yes FTP: FILE TRANSFER PROTOCOL UPLOADING AND DOWNLOADING PORT NUMBER 20/21 ( default port) home dir (/var/ftp/pub default user (anonymous ) vsftp : very secure file transfer protocol File : server to client(download) client to server (upload) Practical 1 (Server[linux]-client[linux]) linux ftp server installation: #rpm -qa | grep vsftp* #yum install vsftp* #cd /etc/vsftpd #vivsftpd.conf #service vsftpd restart #chkconfig vsftpd on for testing #cd /var/ftp/pub #touch file1 file2 file3 ------------------------ ----------------------------------------------------------------------- Linux Client: ----------------- #rpm -qa | grep ftp* #yum install ftp Text Mode Client verify #ftp <ip of server> command for upload a single file /multiple fileput filename mput * command for download a single file/multiple file get<filename> mget * GUI MODE CLIENT #yum install gftp* application --> internet->gftp FIREWALL TCP WRAPPERS service based firewall /etc/hosts.allow /etc/hosts.deny if duplicate entries in both file control set the priorities for allow entry the control look out the allow file, if allow file it go for deny file if both file existed, first it goto the allow and deny file PRACTIAL how to block the telnet IPTABLE (ipchanins) ipaddress& port number basis NIS SERVER(YELLOW PAGES) NETWORK INFORMATION SERVICES CLIENT /SERVER ARCHITECTURE INLINUX server configuration --------------------- #vi /etc/sysconfig/network NISDOMAIN= “STS” #service ypserv restart #service ypbind restart [ client/server] #service yppasswdd restart #service ypxfrd restart #nisdomainname [ it show the domain name] u must initialize the nis database File promising CHMODE R : 4 w : 2 x : 1 775 (user) (g) (other) --------------------------------------------------------------------- Inode Information node [root@server1 covai]# ll -i total 0 523539 -rw-r--r--. 1 root root 0 Jan 25 13:29 file1 523814 -rw-r--r--. 1 root root 0 Jan 25 13:29 file2 [root@server1 covai]# inode table: When u copy a file the inode number will be change or not? It create a new inode When u move a file the inode number will be change or not? It will not be change When u rename a file the inode number will be change or not? It will not change ---------------------------------------------------------------------- Search The Data In The Vi Editor / : forward search ? : reverse search Open a file with read only #vi -R file1 3dd : delete a 3 line ---------------------------------------------------------------------- Sudo User: Normal user act like a root user sudo permission can only implement by root user $system-config-users 1) With password permission #visudo 78 rajan ALL= (ALL) ALL $sudo system-config-users 2) without password permission 78 rajan ALL=(ALL) NOPASSWD: ALL $sudo system-config-users ---------------------------------------------------------------------- # cat /var/log/messages dmesg : it show the details of what happend at booting time df -h du - tr : translate tee : it write the output to the file and also show the output in console REGULAR EXPRESSION ------------------- * : any number of character ? : single character NFS: NETWORK FILE SYSTEM · SHARE THE FILES BETWEEN LINUX/LINUX orUnix based system · NFS is protocol, it share the files · port number : 2049 NFS · port number : 111 PORTMAP NFS SERVER CONFIGURATION( text/default gui/webmin) File Server [Linux-Linux or UNIX based System] 1. #rpm -qa | grep nfs # yum install nfs # cd /etc 2. #vi exports /tmp/covai 192.168.1.101(rw,sync)[ particular host] 192.168.1.0(rw,sync) [ particular network] *(rw,sync) /backup/redhatdvd *(rw,sync) :wq 3. #/usr/sbin/exportfs -av -a all V verbose activate the all share in the config file exporting ( /tmp/covai) 4. #service nfs restart #service portreserve restart [el6] #service portmap restart [ el5] #chkconfig nfs on #chkconfig portreserve on #rpcinfo -p localhost [it show the port are running properly or not] TEST IN LOCAL How to view what are the data mounted? #mount NFS CLIENT CONFIG: #rpm -qa | grep nfs #yum install nfs #service portmap restart #service nfs restart #setup [nfs should be enabled] TEMPORARY MOUNT #mount <source><destination> #mount 192.168.1.101:/tmp/covai /mnt[] PERMANENT MOUNT 1.modify the fstab 2.modifyautofs #vi /etc/auto.misc #vi /etc/auto.master #service autofs restart #chkconfig autofs on ---------------------------------------------------------------------- internet 256 Request APACHE:Web Server www.yahoo.com --DNS (name based) It locate your data in the net/find the data in the net http://192.168.1.101<yahoo> http://192.168.1.102<Hotmail> In Single PC (Server) how many web site can be host? Single NIC: 255 IP PORT NUMBER: 0 – 65536 (port number can be generate) (0-1024 well defined port using by system) 192.168.1.1:1 www.hotmail.com(/var/www/html/hotmail) 192.168.1.1:2 www.yahoo.com(/var/www/html/yahoo) Virtual ip hosting 1:65536 Single card (1) * 255 *65536 ----------------------------------------------------------------------------------------- Single Web Site Hosting(IP Based) http: 80 https :443 Apache Server Config: # rpm -qa | grep http #yum install http* #cd /etc/httpd/config #vi httpd.conf {Do the configuration} #service httpd restart #chkconfig httpd on Testing : http://localhost/ {for test page) http://192.168.1.101 1. gui mode browser http://192.168.1.101 2. #elinkshttp://192.168.1.101 [ default in dvd : install by yum] 3. #lynx http://192.168.1.101 ------------------------------------------------------------------------------------------ Home dir /var/www/html <index.html> --------------------------------------------------------------------------------------- Virtual IP Address: #cd /etc/sysconfig-scripts/ [EL6] #ls #vi ifcfg-eth0 IPADDR=129.168.1.101 PREFIX=24 IPADDR=129.168.1.102 PREFIX=24 #cd /etc/sysconfig/network-scripts #ls #cp ifcfg-eth0 ifcfg-eth0:1 #vi ifcfg-eth0:1 DEVICE eth0:1 IPADR=192.168.1.201 APACHE WITH PASSWORD 1.Createa two file a).htaccess b).htpasswd #vi/var/www/html/hotmail/.htaccess #vivar/www/html/hotmail/.htpasswd (should be in web directory) --------------------------------------------------------------------------------------------------------------------- #vi/var/www/html/hotmail/.htpasswd AuthName "LOGIN " AuthType Basic <Limit GET POST> require valid-user </Limit> --------------------------------------------------------------------------------------------------------------------- #cd /var/www/html/hotmail Create password [root@server2 hotmail]# htpasswd -c .htpasswdrajan New password: Re-type new password: Adding password for user rajan --------------------------------------------------------------------------------------------------------------------- HTTP VERBS GET: IT SHOW PARAMETER DETAILS IN ADD.BAR POST: IT DOES NOT SHOW #Service httpd restart http://192.168.1.202 --------------------------------------------------------------------------------------------------------------------- #ifconfig #iwconfig #ip add show #ip link show #hdparm -i /dev/sda #cat /proc/partitions #fdisk -l #df -h #du /etc / [disk usage] #dmidecode #lsusb #lspci #dmesg [ it show the details of the boot time] --------------------------------------------------------------------------------------------------------------------- Linux Booting Process ------------------------- 1. power on 2. Post ( power on self test) 3. MBR ( Master boot record : in disk first sector 512 bytes)[grub] 4. lookup the booting files & load the kernel image/boot/grub 5. it start the first process in linux (init load the system) 6. init call /etc/rc.d/rc.sysinit 7. it lookup the /etc/inittab& /etc/fstab 8. it load the process from the /etc/rc.d/ <runlevel folder> 9. login prompt will be applear --------------------------------------------------------------------------------------------------------------------- Process Schedule in Linux One time process (at) #at 5pm #atq[ list of bending] #atrm<jobnumber> #cat /etc/at.allow #cat /etc/at.deny #cat /etc/cron.allow #cat /etc/cron.deny [root@server1 rc.d]# at 5PM at> tar -cvf /tmp/backup/test.tar /mydata at> cd /mydata at> rm -rf * at> poweroff at><EOT> job 1 at 2012-02-07 17:00 [root@server1 rc.d]# at 4PM at> cp /backup/* /tmp/backup/ at> rm /backup/* at><EOT> job 2 at 2012-02-07 16:00 1. daily schedule at 5PM ) CRON TAB HAS 6 FILEDS 2. minute (059) 3. hour (023) 4. day of month (131) 5. month (112, or name such as jan, feb, etc) 6. day of week ( 06(6 = Sunday) or name such as mon, tue,etc) 7. command to run #crontab -e [ edit the crontab] #crontab -l [ list of job] #crontab -r [ delete all job] --------------------------------------------------------------------------------------------------------------------- Network Diagnostic Tools · ping [ default will be infinity] · ping -c 5 192.168.1.102 · traceroute [ it analyses the packet path] · host · dig · netstat · Connected users: w · Recent Logins: last, lastb · iwconfig --------------------------------------------------------------------------------------------------------------------- Switchdesk Change the d #ip link showesktop session ------------------------------------------------------ · chkconfig –list | less · cat /etc/services · all port number with the service name · system-config-services · setup · serviceconf · top · ps -A

GroupATC IT Solutions

Server 2012

LINUX