Red Hat System Administration I

1. Display the first 12 lines of the /usr/bin/clean-binary-files file and send the command output to the /home/student/headtail.txt file.

   [student@serverX ~]$ head -n 12 /usr/bin/clean-binary-files >/home/student/headtail.txt

2. Display the last nine lines of the /usr/bin/clean-binary-files file and add the command output to the /home/student/headtail.txt file.

   [student@serverX ~]$ tail -n 9 /usr/bin/clean-binary-files >>/home/student/headtail.txt

1. Create a total of 30 files with names system_changes-machineY-month_Z.txt. Replace Y with the machine number and replace Z with the months jan, feb, and mar.

   [student@serverX ~]$ touch ~student/system_changes-machine{1..10}-month_{jan,feb,mar}.txt

2. Create the /home/student/syschanges directory with the subdirectories jan, feb, and mar.

   [student@serverX ~]$ mkdir -p /home/student/syschanges/{jan,feb,mar}

3. Sort all newly created files by month into the corresponding subdirectory.

   [student@serverX ~]$ mv ~student/system_changes-machine*jan.txt /home/student/syschanges/jan/
   [student@serverX ~]$ mv ~student/system_changes-machine*feb.txt /home/student/syschanges/feb/
   [student@serverX ~]$ mv ~student/system_changes-machine*mar.txt /home/student/syschanges/mar/

4. Remove all newly created files related to machine 9 and 10.

   [student@serverX ~]$ rm -f /home/student/syschanges/*/system_changes-machine{9,10}*.txt

1. Look up the relevant option in the ls(1) man page to determine how to prevent ls from providing colorful output. What is the correct option?

   [student@serverX ~]$ man ls

   ls uses --color=never to turn off colors in the command output.

2. Create the text file /home/student/lscolor.txt with the ls option to turn off colorful output.

   [student@serverX ~]$ echo "--color=never" >/home/student/lscolor.txt

1. Copy the file /home/student/vimfile.txt to /home/student/longlisting.txt.

   [student@serverX ~]$ cp /home/student/vimfile.txt /home/student/longlisting.txt

2. Edit the file using Vim, to take advantage of visual mode.

   [student@serverX ~]$ vim /home/student/longlisting.txt

3. Remove the owner column from the file.

   Use the arrow keys to position the cursor at the first character of the user owner column. Enter visual mode with Ctrl+v. Use the arrow keys to position the cursor at the last character and row of the user owner column. Delete the selection with x.

4. Remove the Documents and Pictures rows. This time, enter visual mode with an uppercase V, which automatically selects full lines.

   Use the arrow keys to position the cursor at any character on the Documents row. Enter visual mode with an uppercase V. The full line is selected, as shown in the screen shot. Delete the selection with x. Repeat for the Pictures row.

5. Save the file and exit the editor.

   Press the "esc" key and enter ":wq" to write the file and exit vim.

1. Change the default system settings for newly created users to ensure their passwords are changed at least every 60 days.

   [student@serverX ~]$ sudo vim /etc/login.defs
   [student@serverX ~]$ cat /etc/login.defs
   ...Output omitted...
   PASS_MAX_DAYS	60
   PASS_MIN_DAYS	0
   PASS_MIN_LEN	5
   PASS_WARN_AGE	7
   ...Output omitted...
   

2. Create a new group named instructors with a GID of 30000.

   [student@serverX ~]$ sudo groupadd -g 30000 instructors
   [student@serverX ~]$ tail -5 /etc/group 
   stapdev:x:158:
   pesign:x:989:
   tcpdump:x:72:
   slocate:x:21:
   instructors:x:30000:
   

3. Create three new users: gorwell, rbradbury, and dadams, with a password of firstpw and add them to the supplementary group instructors. The primary group should remain as the user private group.

   [student@serverX ~]$ sudo useradd -G instructors gorwell
   [student@serverX ~]$ sudo useradd -G instructors rbradbury
   [student@serverX ~]$ sudo useradd -G instructors dadams
   [student@serverX ~]$ tail -5 /etc/group     
   slocate:x:21:
   instructors:x:30000:gorwell,rbradbury,dadams
   gorwell:x:1001:
   rbradbury:x:1002:
   dadams:x:1003:
   [student@serverX ~]$ sudo passwd gorwell
   Changing password for user gorwell.
   New password: firstpw
   BAD PASSWORD: The password is shorter than 8 characters
   Retype new password: firstpw
   passwd: all authentication tokens updated successfully.
   [student@serverX ~]$ sudo passwd rbradbury
   [student@serverX ~]$ sudo passwd dadams
   

4. Determine the date 60 days in the future and set each of the three new user accounts to expire on that date.

   [student@serverX ~]$ date -d "+60 days"
   Mon April  5 11:49:24 EDT 2014
   [student@serverX ~]$ sudo chage -E 2014-04-05 gorwell
   [student@serverX ~]$ sudo chage -E 2014-04-05 rbradbury
   [student@serverX ~]$ sudo chage -E 2014-04-05 dadams
   

5. Change the password policy for the gorwell account to require a new password every 10 days.

   [student@serverX ~]$ sudo chage -M 10 gorwell
   [student@serverX ~]$ sudo chage -l gorwell
   Last password change                                    : Feb 04, 2014
   Password expires                                        : Feb 14, 2014
   Password inactive                                       : never
   Account expires                                         : April 05, 2014
   Minimum number of days between password change          : 0
   Maximum number of days between password change          : 10
   Number of days of warning before password expires       : 7
   

6. Force all three newly created users to change their password on first login.

   [student@serverX ~]$ sudo chage -d 0 gorwell
   [student@serverX ~]$ sudo chage -d 0 rbradbury
   [student@serverX ~]$ sudo chage -d 0 dadams
   

1. Open a terminal window and become root on serverX.

   [student@serverX ~]$ su -
   Password: redhat
   [root@serverX ~]#

2. Create the /home/instructors directory.

   [root@serverX ~]# mkdir /home/instructors

3. Change group permissions on the /home/instructors directory so it belongs to the group instructors.

   [root@serverX ~]# chown :instructors /home/instructors

4. Set permissions on the /home/instructors directory so it is a set GID bit directory (2), the owner (7) and group (7) have full read/write/execute permissions, and other users have read permission (4) to the directory.

   [root@serverX ~]# chmod 2774 /home/instructors 

5. Check that the permissions were set properly.

   [root@serverX ~]# ls -ld /home/instructors
   drwxrwsr--. 2 root instructors 1024 Dec 9 1:38 /home/instructors

1. In a terminal window, run the top utility. Size the window as tall as possible. Top sorts all processes by CPU utilization. The cpuhog process is the one with the highest CPU usage.

   [root@serverX ~]# top
   top - 12:47:46 up  2:02,  3 users,  load average: 1.67, 1.25, 0.73
   Tasks: 361 total,   6 running, 355 sleeping,   0 stopped,   0 zombie
   %Cpu(s): 98.5 us,  1.4 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.1 si,  0.0 st
   KiB Mem:   2043424 total,   897112 used,  1146312 free,     1740 buffers
   KiB Swap:  4079612 total,        0 used,  4079612 free.   296276 cached Me
   
     PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND
    4019 root      20   0    4156     76      0 R 57.5  0.0   2:54.15 cpuhog
    2492 student   20   0 1359500 168420  37492 S 16.8  8.2   3:55.58 gnome-shell
    1938 root      20   0  189648  35972   7568 R  1.9  1.8   0:29.66 Xorg
    2761 student   20   0  620192  19688  12296 S  0.4  1.0   0:04.48 gnome-termi+
   output truncated

2. Exit the top display.

   Press q to quit.

3. Terminate the cpuhog process using the command line. Confirm that the processes no longer display in top.

   [root@serverX ~]# pkill cpuhog

1. Stop the cups service.

   [student@serverX ~]$ sudo systemctl stop cups
   [student@serverX ~]$ sudo systemctl status cups

2. Configure the cups service so that it does not start at system boot.

   [student@serverX ~]$ sudo systemctl disable cups
   [student@serverX ~]$ sudo systemctl status cups

1. Generate a SSH public key on serverX as user student.

   [student@serverX ~]$ ssh-keygen
   

2. Install the SSH public key generated previously on serverX to the student account on desktopX.

   [student@serverX ~]$ ssh-copy-id desktopX
   /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
   /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
   student@desktopX's password: student
   
   Number of key(s) added: 1
   
   Now try logging into the machine, with:   "ssh 'student@desktopX'"
   and check to make sure that only the key(s) you wanted were added.
   
   

3. Log in, then change to the root account, on the serverX virtual machine.

   [student@serverX ~]$ su -

4. Customize the ssh service on serverX by disabling SSH connections for the user root and only allow key-based login.

   Set the necessary configuration file parameters in /etc/ssh/sshd_config:

   PermitRootLogin no
   PasswordAuthentication no

5. Restart the sshd service on serverX.

   [root@serverX ~]# systemctl restart sshd

6. On a different terminal window on desktopX, validate that user root cannot connect to serverX with the ssh command. It should fail because we disabled root logins with the ssh service.

   [student@desktopX ~]$ ssh root@serverX
   Password: redhat
   Permission denied, please try again.
   Password: redhat
   Permission denied, please try again.
   Password: redhat
   Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
   

1. Identify the correct time zone for Bahamas on serverX.

   [root@serverX ~]# tzselect
   Please identify a location so that time zone rules can be set correctly.
   Please select a continent or ocean.
    1) Africa
    2) Americas
    3) Antarctica
    4) Arctic Ocean
    5) Asia
    6) Atlantic Ocean
    7) Australia
    8) Europe
    9) Indian Ocean
   10) Pacific Ocean
   11) none - I want to specify the time zone using the Posix TZ format.
   #? 2
   Please select a country.
    1) Anguilla                 28) Haiti
    2) Antigua & Barbuda        29) Honduras
    3) Argentina                30) Jamaica
    4) Aruba                    31) Martinique
    5) Bahamas                  32) Mexico
    6) Barbados                 33) Montserrat
   ... output omitted ...
   26) Guatemala                53) Virgin Islands (US)
   27) Guyana
   #? 5
   
   The following information has been given:
   
   	Bahamas
   
   Therefore TZ='America/Nassau' will be used.
   Local time is now:	Fri Mar  7 09:38:50 EST 2014.
   Universal Time is now:	Fri Mar  7 14:38:50 UTC 2014.
   Is the above information OK?
   1) Yes
   2) No
   #? 1
   
   You can make this change permanent for yourself by appending the line
   	TZ='America/Nassau'; export TZ
   to the file '.profile' in your home directory; then log out and log in again.
   
   Here is that TZ value again, this time on standard output so that you
   can use the /usr/bin/tzselect command in shell scripts:
   America/Nassau
   

2. Change the time zone to America/Nassau on serverX.

   [root@serverX ~]# timedatectl set-timezone America/Nassau

3. Verify the time zone has been properly set on serverX.

   [root@serverX ~]# timedatectl
         Local time: Wed 2014-04-09 18:21:06 CEST
     Universal time: Wed 2014-04-09 16:21:06 UTC
           RTC time: Wed 2014-04-09 16:21:06
           Timezone: America/Nassau (CEST, +0200)
        NTP enabled: yes
   NTP synchronized: no
    RTC in local TZ: no
         DST active: yes
    Last DST change: DST began at
                     Sun 2014-03-30 01:59:59 CET
                     Sun 2014-03-30 03:00:00 CEST
    Next DST change: DST ends (the clock jumps one hour backwards) at
                     Sun 2014-10-26 02:59:59 CEST
                     Sun 2014-10-26 02:00:00 CET

[root@serverX ~]# echo "journalctl --since 9:05:00 --until 9:15:00" >/home/student/systemdreview.txt

1. Add the directive to log authpriv.alert syslog messages to the /var/log/auth-errors file in the /etc/rsyslog.d/auth-errors.conf configuration file.

   [root@serverX ~]# echo "authpriv.alert /var/log/auth-errors" >/etc/rsyslog.d/auth-errors.conf

2. Restart the rsyslog service on serverX.

   [root@serverX ~]# systemctl restart rsyslog

3. Use logger to create a new log entry to /var/log/auth-errors on serverX.

   [root@serverX ~]# logger -p authpriv.alert "Logging test authpriv.alert"

4. Verify the message sent to syslog with the logger command appears in the /var/log/auth-errors file on serverX in the terminal with tail /var/log/auth-errors.

   [root@serverX ~]# tail /var/log/auth-errors
   Feb 13 11:21:53 server1 root: Logging test authpriv.alert

1. Create a new static network connection using the settings in the table. Be sure to replace the X with the correct number for your systems.

   [root@serverX ~]# nmcli con add con-name review ifname eth0 type ethernet ip4 172.25.X.11/24 gw4 172.25.X.254
   [root@serverX ~]# nmcli con mod "review" ipv4.dns 172.25.254.254
   

2. Configure the new connection to be autostarted. Other connections should not start automatically.

   [root@serverX ~]# nmcli con mod "review" connection.autoconnect yes
   [root@serverX ~]# nmcli con mod "System eth0" connection.autoconnect no
   	

3. Modify the new connection so that it also uses the address 10.0.X.1/24.

   [root@serverX ~]# nmcli con mod "review" +ipv4.addresses 10.0.X.1/24
   

   Or alternately:

   [root@serverX ~]# echo "IPADDR1=10.0.X.1" >> /etc/sysconfig/network-scripts/ifcfg-review
   [root@serverX ~]# echo "PREFIX1=24" >> /etc/sysconfig/network-scripts/ifcfg-review
   

4. Configure the hosts file so that 10.0.X.1 can be referenced as "myhost".

   [root@serverX ~]# echo "10.0.X.1  myhost" >> /etc/hosts
   	

5. Set the host name to serverX.example.com.

   [root@serverX ~]# hostnamectl set-hostname serverX.example.com

1. To be able to create the target directory /configbackup, switch to the root user account with the su command.

   [student@serverX ~]$ su -
   Password: redhat
   [root@serverX ~]# 

2. Create the target directory for the configuration files on serverX.

   [root@serverX ~]# mkdir /configbackup

3. Use the rsync command to synchronize the /etc directory tree on serverX to the /configsync directory on serverX. Be aware that only the root user can read all the content in the /etc directory on serverX.

   [root@serverX ~]# rsync -av /etc /configbackup
   ...

1. Store the /configbackup directory in the /root/configuration-backup-server.tar.gz archive.

   [root@serverX ~]# tar czf /root/configuration-backup-server.tar.gz /configbackup

1. Connect to the serverX machine as user root.

   [student@serverX ~]$ su -
   Password: redhat
   [root@serverX ~]# 

2. Create the target directory /tmp/configcompare/ where the contents of the /root/configuration-backup-server.tar.gz archive will get extracted.

   [root@serverX ~]# mkdir /tmp/configcompare

3. Change to the target directory /tmp/configcompare/ on serverX.

   [root@serverX ~]# cd /tmp/configcompare
   [root@serverX configcompare]# 

4. Extract the contents of the /root/configuration-backup-server.tar.gz archive to the /tmp/configcompare/ directory on serverX.

   [root@serverX configcompare]# tar xzf /root/configuration-backup-server.tar.gz

1. Use ssh to execute the hostname command on desktopX as user student. Send the output of the hostname command to the /tmp/scpfile.txt file on desktopX.

   [root@serverX ~]# ssh student@desktopX 'hostname >/tmp/scpfile.txt'

2. Use scp to copy the /tmp/scpfile.txt file from desktopX to /home/student/scpfile.txt on the serverX machine.

   [root@serverX ~]# scp root@desktopX:/tmp/scpfile.txt /home/student/

Create the file /etc/yum.repos.d/localupdates.repo with the following content:

1. Update the kernel package.

   yum update kernel

2. Install the xsane-gimp package.

   yum install xsane-gimp

3. Install the rht-system package.

   yum install rht-system

4. For security reasons, serverX should not have the wvdial package installed.

   yum remove wvdial

1. Identify the newly added file system with the blkid command on serverX.

   [root@serverX ~]# blkid
   /dev/vda1: UUID="46f543fd-78c9-4526-a857-244811be2d88" TYPE="xfs" 
   /dev/vdb1: UUID="a84f6842-ec1d-4f6d-b767-b9570f9fcdc0" TYPE="xfs"

2. Create the mount point /mnt/datadump on serverX.

   [root@serverX ~]# mkdir /mnt/datadump

3. Mount the file system by UUID on the /mnt/datadump directory of the serverX machine.

   [root@serverX ~]# mount UUID="a84f6842-ec1d-4f6d-b767-b9570f9fcdc0" /mnt/datadump