LFCS Storage Management Practice Question
An administrator has a volume group vg_data with 50 GB of free extents. The logical volume /dev/vg_data/lv_archive is 200 GB and must grow to 350 GB. The administrator runs lvextend -L +150G /dev/vg_data/lv_archive and it fails. Which is the most likely cause?
⚠ Common exam trap
The trap here is blaming the filesystem or the syntax when the real constraint is simply free space in the volume group.
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
✓
The volume group does not have enough free extents to satisfy the 150 GB request.
lvextend allocates physical extents from the volume group's free pool. With only 50 GB free, a 150 GB growth request cannot be met, so the command exits with an error before touching the logical volume. The fix is to add capacity to vg_data, for example by creating a physical volume on a new disk and running vgextend, then repeating the lvextend.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The volume group does not have enough free extents to satisfy the 150 GB request.
Why this is correct
lvextend can only allocate from unallocated physical extents in the volume group. With just 50 GB free, a request for 150 GB of additional space cannot be satisfied, so the command fails before any resizing occurs. The administrator must first add a physical volume with vgextend.
- ✗
The logical volume is formatted with XFS, which cannot be extended with lvextend.
Why it's wrong here
lvextend grows the block device regardless of the filesystem on top. XFS can be grown online with xfs_growfs after the block device is enlarged. The filesystem type does not prevent lvextend from succeeding; the failure here is due to insufficient free extents.
- ✗
The +150G syntax is invalid and should be --size 150G instead.
Why it's wrong here
The +150G form is valid and means 'add 150 GB to the current size'. Using -L 150G without a plus sign would instead set the absolute size to 150 GB, which would be a shrink and fail. The syntax is not the cause of this failure.
- ✗
The filesystem must be unmounted before any logical volume can be extended.
Why it's wrong here
Most filesystems used with LVM, including ext4 and XFS, support online growth. lvextend itself does not require the volume to be unmounted; it operates on the block device. Unmounting is only needed when shrinking a logical volume or filesystem, not when extending.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Linux Foundation exam blueprint
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.