LFCS Storage Management Practice Question
A system administrator is setting up a new backup server. The server has two 4TB disks /dev/sda and /dev/sdb. The administrator decides to create a RAID1 array and then an LVM volume group on top of the RAID device. After creating the RAID1 array /dev/md0, they create a physical volume, volume group named vg_backup, and a logical volume lv_data of size 2TB. Then they format with ext4 and mount at /backup. During testing, they realize that the backup data volume will likely exceed 2TB eventually. They want to expand the filesystem to use all available space in the RAID array. What is the correct procedure?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
lvextend -l +100%FREE /dev/vg_backup/lv_data, resize2fs /dev/vg_backup/lv_data.
Lvextend -l +100%FREE extends the logical volume to use all free space in the volume group, and resize2fs can grow the ext4 filesystem online without requiring unmounting. Option B is incorrect because unmounting is unnecessary for online resize. Option C does not use all available space in one filesystem. Option D is unnecessary as the RAID array already has sufficient space; the goal is to expand the filesystem within the existing volume group.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
lvextend -l +100%FREE /dev/vg_backup/lv_data, resize2fs /dev/vg_backup/lv_data.
Why this is correct
Correct: Online extension without unmount.
- ✗
Unmount /backup, lvextend -l +100%FREE /dev/vg_backup/lv_data, resize2fs /dev/vg_backup/lv_data, mount /backup.
Why it's wrong here
Unmounting is not required; resize2fs works on mounted ext4.
- ✗
Create a new logical volume and mount it separately.
Why it's wrong here
This splits storage but does not consolidate into one filesystem.
- ✗
Add new disk to RAID array, then extend LVM.
Why it's wrong here
Not needed; free space exists in volume group from the RAID array.
Quick reference
RAID Level Comparison
| RAID Level | Min Disks | Fault Tolerance | Read | Write | Usable Capacity |
|---|---|---|---|---|---|
| RAID 0 | 2 | None | Excellent | Excellent | 100% |
| RAID 1 | 2 | 1 disk | Good | Moderate | 50% |
| RAID 5 | 3 | 1 disk | Good | Moderate | 67–94% |
| RAID 6 | 4 | 2 disks | Good | Lower | 50–88% |
| RAID 10 | 4 | 1 disk per mirror | Excellent | Good | 50% |
RAID is not a backup strategy — it protects against disk failure but not against accidental deletion, ransomware, or site-level events.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This LFCS practice question is part of Courseiva's free Linux Foundation certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the LFCS exam.