RHCSA exam prep: objective-by-objective labs
You practise each RHCSA objective in its own lab, unguided, and confirm that it survives a reboot.
Level 201 · 20 lessons · 18 practice labs
Lessons
Essential tools and files
- Finding, archiving and compressing files
- Links and standard permissions
- Redirection, grep and regular expressions
- A simple shell script with conditions and loops
- Short task: find certain files and archive them with their permissions
Running systems and boot
- Resetting the root password at boot
- Finding, prioritising and killing processes
- Enabling services and timers at boot
- Finding logs and making them persistent
- Short task: get back into a server you are locked out of and fix its services
Storage
- Partitions, physical volumes, volume groups and logical volumes
- Growing a logical volume together with its file system
- Set-GID and the sticky bit on shared directories
- Mounting home directories with NFS and autofs
- Short task: create the project volume, grow it and share it with the team
Networking, security and containers
- Configuring IPv4 and IPv6 with nmcli
- firewalld zones, services and port rules
- SELinux contexts, port labels and booleans
- Starting a rootless container as a user service
- Capstone: apply every objective back to back on one server
Practice labs
- Pick out the active lines of a config file: You strip comments and blank lines from a configuration file and write only the active settings to a new file.
- Capture a subnet and dates with a regular expression: With an extended regular expression you select and count log lines from a given subnet within a given range of days.
- Send output and errors to separate files: You redirect the results and permission errors of a find over the whole file system to separate files and summarise the failing directories with a regex.
- Point a symbolic link at the current release: In an application directory you repoint the symbolic link named current at the new release folder and show the old one is intact.
- Find hard links by inode number: You find every hard link of a file by its inode number and prove the data remains after deleting one.
- Scan and fix files with special permissions: You list the setuid, setgid and world-writable files on the server, remove the special bit from two that no package ships and record why.
- Boot once into the rescue target: You edit the kernel line in the GRUB menu to boot once into the rescue target and return to the normal target.
- Reset a forgotten root password with rd.break: You interrupt boot with rd.break, remount the root file system writable, change the password and trigger an SELinux relabel to get back in.
- No password and a broken fstab: get back in: On a server with an unknown root password that drops to emergency mode over a bad fstab line you reset the password, fix the line and restore normal boot.
- Grow an XFS logical volume by 500 MB: You grow a logical volume by 500 MB from free space in its volume group and extend the XFS file system at the same time.
- Grow a volume when the volume group is full: With no space left in the volume group you add a new partition to it and take an ext4 logical volume to exactly 2 GB.
- Bring a volume into the required range and verify persistence: You grow Pusulam Sigorta's archive volume to between 1.4 and 1.6 GB and prove the size after a reboot with mount point and fstab intact.
- Mount an NFS share by hand and test it: You list the shares exported by the lab NFS server, mount one read-only and read its contents.
- Set up an on-demand mount with a direct map: You write an autofs direct map so the NFS share mounts by itself when /mnt/raporlar is entered.
- Mount remote home directories with a wildcard map: You mount central users' home directories with a wildcard indirect map and verify by logging in as one user who can write.
- Turn on an SELinux boolean persistently: You find and persistently enable the boolean that lets the web server serve user home directories.
- Fix a web server that cannot serve content from NFS: You read from the audit log the access error of a web server whose content lives on NFS and enable the right boolean persistently.
- Repair a mislabelled directory tree: You compare an application tree carrying wrong contexts after files were moved with mv against the default rules, fix it in bulk and write a custom rule for one exception.
About this course
You practise each RHCSA objective in its own lab, unguided, and confirm that it survives a reboot.
What you will learn
- Essential tools and files
- Running systems and boot
- Storage
- Networking, security and containers
Prerequisites
Finishing the level 101 courses of the same path, or knowing those topics, is enough.
Lab environment
Lessons run in your own Kali Linux terminal in the browser, connected to a private lab network. Nothing to install.
Frequently asked questions
- Is this course right for my level?
- The course is at level 201; it assumes you know the topics of the lower-level courses.
- Is there anything to install?
- No. Every lesson runs in your own lab environment that opens in the browser.
- How do lessons work?
- Each lesson has 8 to 10 steps and a short quiz. Early steps show the command to type, later steps give less help; if two attempts fail, the solution opens.
- Can I try it for free?
- Yes. The first three lessons of every course are free.