Tag: redhat

  • rpm verify packages

    To verify a package installed on system, you can use

    rpm -V PKG_NAME

    Example

    [root@hello-1 curl-curl-7_69_0]# rpm -V bind
    S.5....T.  c /etc/named.conf
    [root@hello-1 curl-curl-7_69_0]# 

    Here bind package have /etc/named.conf file modified.

    To verify all packages on system, run

    rpm -Va

    Back to rpm

  • RHCSA Study Guide

    1. Logical volume ‘home’ as created and mounted. Reduce its size to ‘192M’ (size from 185M to 200MB is acceptable)

    # lvdispaly
    # umount /dev/vgsrv/home
    # e2fsck -f /dev/vgsrv/home
    # resize2fs /dev/vgsrv/home 192M 
    # lvcreduce -L 192M /dev/vgsrv/home
    # mount /dev/vgsrv/home
    # lvdisplay
    
    
    # lvdisplay
    # umount /dev/vgsrv/home
    # lvextend -L 256M /dev/vgsrv/home
    # e2fsck -f /dev/vgsrv/home
    # resize2fs /dev/vgsrv/home 256M
    # mount /dev/vgsrv/home
    # lvdisplay
    

    2. Add a group sysmgrs

    Add a user Natasha such that user’s secondary group is sysmgrs.

    Add a user harry such that user’s secondary group is sysmgrs.

    Add a user sarrah, who has no interactive shell, and not belongs to the group sysmgrs.

    Set password of Natasha, harry and sarrah to lotawens.

    # groupadd sysmgrs
    # useradd -G sysmgrs Natasha
    ( We can verify the newly created user by cat /etc/passwd)
    # useradd -G sysmgrs harry
    # useradd -s /sbin/nologin sarrh
    # passwd Natasha
    # passwd harry
    # passwd sarrah
    

    3. Configure FTP access on your virtual machine to allow permission for anonymous user.

    If yum not configured;
    # cd /etc/yum.repos.d
    # vim domain70.repo
    [domain70]
    baseurl=
    enabled=1
    gpgcheck=0
    :wq!
    
    # yum clean all
    # yum update all
    
    # yum install vsftpd*
    # yum install ftp
    # ftp ip
    User: anonymous
    Password: 
    
    If logging successfully, do the last steps;
    If not, the below mentioned files and make changes.
    # vim /etc/vsftpd/vsftpd.conf
    # vim /etc/vsftpd/ftpusers
    # vim /etc/vsftpd/user_list
    And try again
    # service vsftpd restart
    # chkconfig vsftpd on
    

    4. Make a collaborative directory /a/b and set the permission as

    Group ownership of /a/b is sysmgrs

    The directory should be readable, writable and accessable to members of sysmgrs, but not to any other user. ( it is undershould that root has access to all files and
    directories on the system)

    Files created in /a/b automatically have group ownership set to the group sysmgrs.

    # mkdir -p /a/b
    # chgrp sysmgrs /a/b
    # chmod 2770 /a/b
    

    5. Copy the file /etc/fstab to /var/tmp. Configure the permissions of /var/tmp/fstab so that,

    The file /var/tmp/fstab is owned by the root user

    The file /var/tmp/fstab is belongs to group root

    The file /var/tmp/fstab is should not be executable by anyone

    The user natasha is able to read and write /var/tmp/fstab

    The user harry can neigher write not read /var/tmp/fstab

    All other users (current or future) have the ability to read /var/tmp/fstab

    # cp -a /etc/fstab /var/tmp
    # cd /var/tmp
    # ls -l
    # getfacl /var/tmp/fstab
    # chmod ugo-x /var/tmp/fstab 
    [ No need to do this, there won't be execute permission for the file by default]
    # setfacl -m u:natasha:rw /var/tmp/fstab
    # setfacl -m u:harry:0 /var/tmp/fstab   (zero)
    [Read permission will be there for all the users, by default. Check it using ls -l /var/tmp/fstab]
    
    Verify by
    
    [ ls -la /var/tmp/fstab]
    
    

    6. set cronjob for user natasha to do /bin/echo hiya at 14:23

    # crontab -e -u natasha
    23 14 * * * /bin/echo hiya
    :wq!
    

    7. host.domain70.example.com shares remote users. Configure ldap such that ldapusers has no home directory until we do automounting.

    baseDN: dc=domain70, dc=example, dc=com

    Certificate: ftp://host.domain70.example.com/pub/EXAMPLE-CA-CERT

    Username: ldapuser70

    Password: password

    # system-config-authentication
    LDAP user
    DN=dc=domain70,dc=example,dc=com
    Server=host.domain70.example.com
    Certificate= ftp://host.domain70.example.com/pub/exam-crt ( enter url carefully, there maybe // or ..)
    LDAP password
    OK
    
    starting sssd
    # su -ldapuser70
    Display Bash prompt
    #exit
    

    8. configure NTP with that of rhcert.domain70.example.com

    # system-config-date
    Delete old server names and add given server name 
    Advanced Tick speedup
    #exit
    

    9. Implement a web server for the site http://station.domain70.example.com/ then perform the following steps:

    Download ftp://rhcert.domain70.example.com/pub/rhcsa/station.html

    Rename the download file to index.html

    Copy this index.html to the Document root of your web server.

    DO NOT make any modifications to the content of index.html

    # yum install httpd
    # cd /var/www/html
    # wget ftp://rhcert.domain70.example.com/pub/rhcsa/station.html
    # mv station.html index.html
    990th line : remove '#'
    Remove '*' and add IP address:
    Eg Name VirtualHost 172.40.70.12
    1003rd line copy 7 lines and paste below that itself.
    (last 7 lines)
    Remove # of all lines
    
    Ist line : remove * and add ip
    
    
    3rd line
    
    Document Root /var/www/html
    
    4th line
    
    server name station.domain70.example.com
    :wq!
    
    #service httpd restart
    # chkconfig httpd on
    
    check site http://station.domain70.example.com/
    
    

    10. Install the appropriate Kernel update from ftp://domain70.example.com/pub/updates/ The following criteria must also be met:

    The updated kernel is the default Kernel when the system is rebooted.

    The orginal kernel remains available and bootable on the system.

    # ftp rhcert.domain70.example.com
    Anonymous login
    ftp> cd /pub/updates
    ftp> ls
    ftp> mget kernel*
    ftp> bye
    # rpm -ivh kernel*
    # vim /etc/grub.conf
    Check the updatted kernel is the first kernel and the orginal kernel remains available.
    set default=0
    :wq!
    

    11. Configure autofs to automount the home directories of ldapusers host.domain70.example.com NFS-exports /rhome to your
    machine. ldapuser70’s home directory should be automounted locally beneath /rhome/ldapuser7-. Home directores must be writable by thier users.

    User: ldpauser70
    Password: password

    # vim /etc/auto.master
    /rhome /etc/auto.misc
    :wq!
    # vim /etc/auto.misc
    ldapuser70 --rw,sync host.domain70.example.com:/rhome/ldpauser70
    :wq!
    
    #service autofs restart
    # service autofs reload
    # chkconfig autofs on
    # su -ldapuser70
    Login ldapuser with home directory
    # exit
    

    12. Create a swap partition of 754 MB size. Do not make any change to the existing swap partition

    # fdisk -l
    # fdisk -cu /dev/vda
    p
    n
    e or p
    select e
    default (first): enter
    default (last): enter
    n
    default(first): enter
    default(first): +754M
    t(1-5)
    l: 82
    p
    w
    #reboot
    #mkswap /dev/vda5
    
    
    # vim /etc/fstab
    
    /dev/vda5 swap swap defaults 0 0
    
    :wq
    
    # mount -a
    # swapon -a
    # swapon -s
    
    

    13. Add a user manlo with uid 1353. Set his password as lotawens

    # useradd -u 1353 manlo
    # passwd manlo
    # su - manlo
    

    14. Locate all files and directories of user jacques and copy it to /root/findfiles

    OR locate the files of owner “dax” and copy to the directory /root/founddirectory

    OR Find files in your system which is owned by andrew user & save on /backup/somefile.

    
    # find / -user jacques > /root/findfiles ( if /root/findfiles is a file)
    
    
    # mkdir -p /root/findfiles
    # find / -user jacques -exec cp -a {} /root/findfiles\;    [ if /root/findfiles is a directory ]
    
    

    15. Find all lines contain a string loop in a file /etc/grub.conf copy it to /root/list. Don’t leave a free line in /root/list

    grep loop /etc/hosts > /root/list
    

    16. Create a device:

    Logical volume qa with 60 extents.

    Volume group qagroup with 16MB extent size.

    Mount it permanently under /abc with file system ext3

    
    # fdisk -l
    # fdisk -cu /dev/vda
    n
    default(first)
    default(last): +1000M
    (since 60 extents of 16M = 16*60=960MB lvm;
    So physical volume > 960MB)
    t(1-6):6
    l:8e
    p
    w
    # reboot(init6)
    # pvcreate /dev/vda6
    # vgcreate -s 16M qagroup /dev/vda6
    # lvcreate -l 60 -n qa qagroup
    # mkfs.ext3 /dev/qagroup/qa
    # mkdir /abc
    # vim /etc/fstab
    /dev/qagroup/qa /abc ext3 defaults 0 0
    :wq
    # mount -a