F5CAB1 Install, Initial Configuration, and Upgrade Practice Question
An administrator is upgrading a BIG-IP from v13.1.1 to v16.1.0. During the upgrade, the administrator receives an error that the disk space is insufficient to install the new image. The administrator checks and finds that the `/var` partition is nearly full. What is the most appropriate action to resolve this issue?
⚠ Common exam trap
The trap here is considering resizing partitions or deleting the active image, when the simple and safe solution is to remove unnecessary files from `/var`.
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
✓
Delete old UCS backup files and logs from `/var` to free up space.
Freeing up space on the `/var` partition by deleting old UCS backups and logs is the correct action. This safely reclaims space needed for the new image. Other options involve invalid commands, incorrect installation locations, or deleting critical system files. The administrator should also ensure that other partitions have sufficient space.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Resize the `/var` partition using the `tmsh modify sys disk` command.
Why it's wrong here
The `tmsh modify sys disk` command does not exist for resizing partitions. Disk partitioning on BIG-IP is fixed and cannot be easily resized without reinstallation. Attempting to resize would likely fail and could damage the system. The correct approach is to free up space by removing unnecessary files, not by resizing partitions.
- ✗
Install the new image to the `/shared` partition instead of the inactive volume.
Why it's wrong here
The new image must be installed to an inactive volume, not directly to `/shared`. The `/shared` partition is used for shared files between volumes, such as images and UCS files. Installing the image there would not create a bootable volume and would not resolve the upgrade. The installation process requires a dedicated volume.
- ✗
Use the `tmsh delete sys software image` command to remove the current active image and free space.
Why it's wrong here
Deleting the active image would render the system unbootable and cause a major outage. The active image is the currently running software and must not be removed. The `tmsh delete sys software image` command is used to remove old images from inactive volumes, but not the active one. This action would be catastrophic and is not appropriate.
- ✓
Delete old UCS backup files and logs from `/var` to free up space.
Why this is correct
The `/var` partition often contains logs, UCS backups, and other temporary files that can consume significant space. Deleting old UCS files and logs is a safe and effective way to free up space for the new image. This action addresses the root cause without affecting system functionality. The administrator should also consider rotating logs and removing unnecessary files.
Visual reference
About these practice questions
This F5CAB1 question is part of Courseiva's 80-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official F5 exam blueprint
This F5CAB1 practice question is part of Courseiva's free F5 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 F5CAB1 exam.