http://ssl.webangel.ie/ 2026-05-28T11:37:59+00:00 http://ssl.webangel.ie/ http://ssl.webangel.ie/lib/exe/fetch.php?media=wiki:dokuwiki.svg text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:file-systems&rev=1759832057&do=diff File Systems interesting command to use is blkid this is useful to get information about partitions. if they are formated or not and the UUID of them by default partitions are now mounted using UUIds in fstab you can also use lsblk -fp lsblk -fs text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:insights&rev=1759832057&do=diff Detect and Resolve issues with Red Hat Insight Red Hat Insights is a predictive analytics tool to help you to identify and remediate threats to security, performance, availability, and stability on systems in your infrastructure that run Red Hat products. Red Hat delivers Red Hat Insights as a Software-as-a-Service (SaaS) product text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:manage&rev=1759832057&do=diff Analyse and Manage other Systems This is done using the Web Console and ituses cockpit this is a service that is installed by default but it needs to be enabled need to open firewall port 9090 or adding the cokpit service to firewalld [root@host ~]# firewall-cmd --add-service=cockpit --permanent success [root@host ~]# firewall-cmd --reload success text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:monitor&rev=1759832057&do=diff Monitor and Manage Processes Using PS Using PS to monitor processes ps aux | grep bash look for any bash processes. Showing multiple states [user@host ~]$ ps aux USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND ...output omitted... root 2 0.0 0.0 0 0 ? S 11:57 0:00 [kthreadd] student 3448 0.0 0.2 266904 3836 pts/0 R+ 18:07 0:00 ps aux ...output omitted... text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:network&rev=1759832057&do=diff Manage Networking Service configuration files are stored in the /etc/NetworkManager/system-connections/ directory. nmcli a staple for network management Here are some nmcli command options and what they do option function nmcli dev status text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:package&rev=1759832057&do=diff Package Management Install and Update Software Packages with DNF It stands for Dandified Yum All installation and removal transactions are logged in the /var/log/dnf.rpm.log file The dnf history command displays a summary of installation and removal transactions. Similar to yum history. text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:password&rev=1759832057&do=diff Password Management Chage Use chage to change age etc of a password option what it does M sets maximumum time for password m sets minimum time for password before you can change it E set a password expiration date W how many warning days you get text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:permissions&rev=1759832057&do=diff File Permissions There are 6 permissions in Linux These are the standard ones Read write execute File Type Owning User Owning group Other d (directory) rwx r-x --- There are 3 special permissions Permission effect on directory text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:shell&rev=1759832057&do=diff Shell Variables Name Function HISTFILESIZE change the size of your histfile from default 1000 to whatever you put there HISTTIMEFORMAT=“%F %T This add date and time details to History export LESS=”-X“ leaves the result of cat on the screen text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:ssh&rev=1759832057&do=diff Configure and Secure SSH Configure SSH Key-based Authentication Generating THis allows you to connect to a server without needing to provide a password Basic command to create a ssh key is ssh-keygen a more compley example is ssh-keygen -f .ssh/key-with-pass text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:sudoers&rev=1759832057&do=diff Sudoers Options REdhat recommends rather than modifying the sudioers file itself you and entries to the /etc/sudoers.d/ directory Permissions are similar for example [student@servera ~]$ sudo cat /etc/sudoers.d/operator1 operator1 ALL=(ALL) ALL text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:system_processes&rev=1759832057&do=diff Identify Automatically Started System Processes Systemd Replaces the older and clunkier init. Default as of RH7. Manages various things Services Daemons Path watches files Mount controls mounts Timer scheduling Slice resource management text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:terminal&rev=1759832057&do=diff Terminal Options Main instructions on how to use Tmux Tmux allows you to split your screen and run multiple commands on multiple panes and create separate windows Start tmux by typing tmux It might not be installed Panes command Option text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:user-man&rev=1759832057&do=diff User Management command options Result useradd creates a new user usermod -u used to specify the new users user id usermod -d used to specify the new users home directory usermod -c used to add a comment detail about new user text/html 2025-10-07T10:14:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=classnotes:rh124:vim&rev=1759832057&do=diff Vim Editor option result shift +v enter the visual line editor. Used to select lines on a file use arrows to select more lines ctrl + v same as above but used to select blocks of lines x used to delete whatever you selected enable line numbers with :set nu!