[ norboten ]
rhcsa · lab rhcsa-03

The Volume That Filled Overnight

· about 45 minutes · runs on rocky-10 · unrated

Read the journal Read its source

An unrated lab. It runs on your machine with no account and no network, and everything about it — the faults, the checks, the hints and the reference solution — is in the repository. An attempt on it is recorded on your profile and never moves a rating: only rated labs do. Rated and unrated labs.

The briefing

The application volume, mounted at /var/lib/app, filled up overnight. Someone "fixed" it at 3 a.m. and rebooted. Now the machine does not finish booting and sits waiting at a maintenance prompt.

You cannot SSH in yet. Attach to the console with k on this lab's screen (detach with Ctrl-]). The root password is norboten.

Facts you have been given:

  • The volume group vg0 holds the application's logical volume. A second disk was added to the machine last week "for growth" and never used.
  • The files under /var/lib/app/data are the application's data. They must not be deleted, moved or truncated.
  • The machine used to have swap. It has none now.

What is expected, and graded:

  1. The machine boots cleanly on its own, with /var/lib/app mounted.
  2. /var/lib/app has at least 30% free space, with all its data intact.
  3. Swap is active, and stays active after a reboot.
  4. Filesystems are mounted by UUID or label, never by a raw device name.
  5. No space on /var/lib/app is held by files that no longer exist.

What is graded

The machine is checked, rebooted, and checked again. A check passes only if it passes both times.

CheckObjective
01_boots_cleanConfigure systems to mount file systems at boot by UUID or label
02_app_volume_has_headroomExtend existing logical volumes
03_swap_active_after_rebootAdd new partitions, logical volumes, and swap non-destructively
04_fstab_uses_uuidConfigure systems to mount file systems at boot by UUID or label
05_held_space_releasedDiagnose and correct file permission problems

Start it

  1. 2Labs
  2. rhcsa-03select this one
  3. udownload it
  4. sstart the machine

Reading

Where the lab's hints send you, level by level, as you ask for them (h, then l opens a journal section in the TUI).

Theory for this lab

4 questions on the same topic, in the lab's Theory tab. They never affect the lab's grade. Three of them, to answer here:

Question 1

The volume group has no free extents. Which sequence grows the LV onto a new disk /dev/vdc?

Question 2

Why mount by UUID rather than /dev/vdb1 in /etc/fstab?

Question 3

Which fstab line enables an existing swap file at boot?