LFCS Storage Management Practice Question
An administrator needs to add a new swap space to a running Linux server without rebooting. The server has a free partition /dev/sdc1 and an existing file /swapfile. Which two commands or steps are required to activate the new swap partition /dev/sdc1 immediately? (Choose two.)
⚠ Common exam trap
A common mix-up: candidates confuse the steps for immediate activation with the steps for persistent configuration, such as editing /etc/fstab.
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
✓
swapon /dev/sdc1
To activate a new swap partition immediately, you must first initialize it with mkswap, then enable it with swapon. These two commands prepare and activate the swap space without requiring a reboot. Adding an fstab entry is for persistence across reboots, and swapoff or mount are not appropriate for enabling swap.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
swapoff /dev/sdc1
Why it's wrong here
swapoff disables swap on a device or file. It is the opposite of what is needed here; the administrator wants to activate new swap, not deactivate it. Running swapoff on a device that is not currently active would have no effect, and it does not prepare or enable swap.
- ✗
mount -t swap /dev/sdc1 /mnt
Why it's wrong here
Swap space is not mounted like a regular filesystem. The mount command does not support a swap filesystem type in this manner. Swap is activated with swapon, not mount. Attempting to mount a swap partition would fail because it lacks a mountable filesystem structure.
- ✗
echo '/dev/sdc1 none swap sw 0 0' >> /etc/fstab
Why it's wrong here
Adding an entry to /etc/fstab ensures the swap is activated at boot, but it does not activate the swap immediately. The scenario requires the swap to be available without rebooting. While this step is useful for persistence, it is not part of the immediate activation process.
- ✓
swapon /dev/sdc1
Why this is correct
swapon activates the swap partition, making it available to the kernel for paging. After mkswap has initialized the partition, swapon enables it immediately without a reboot. This is the second required step to bring the new swap space online.
- ✓
mkswap /dev/sdc1
Why this is correct
mkswap initializes the partition as swap space by writing the swap signature. This step is required before the partition can be used for swapping. Without running mkswap, the kernel will not recognize /dev/sdc1 as valid swap, and swapon will fail. This is the first step to prepare the device.
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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
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