🔧 Expanding the Root Logical Volume on ggRock

Some users configure their ggRock Server with a small root LVM (e.g., 16GB or less). This can lead to issues if logs grow rapidly—often triggered by the ggRock array approaching capacity. Expanding your root LVM gives you extra headroom to troubleshoot before system performance is affected.

🧭 Step 1 – Check Current Filesystem Usage

Run the following command to verify the size and usage of your root LVM:

df -h /

Example output:

Filesystem Size Used Avail Use% Mounted on
/dev/mapper/ggrock--vg-root 15G 3.7G 11G 27% /

In this case:

• Path: /dev/mapper/ggrock--vg-root
• Current size: 15G
• Utilization: 27%

📊 Step 2 – Check Available Space in Volume Group

Run the following to check how much space is available in the volume group:

vgdisplay ggrock-vg

Look for the line:

Free PE / Size 52434 / 204.82 GiB

This indicates ~200GB of free space is available for expansion.

➕ Step 3 – Expand the Root LVM

Use the lvextend command to grow your root volume. In this example, we’re adding 2GB:

lvextend -L +2G /dev/mapper/ggrock--vg-root -r

Explanation:

• +2G: Increase by 2GB (you can use M for megabytes)
• -r: Automatically resizes the filesystem

Sample output:

Size of logical volume ggrock-vg/root changed from <14.90 GiB to <16.90 GiB.
Filesystem at /dev/mapper/ggrock--vg-root is now 4429824 (4k) blocks long.

✅ Step 4 – Confirm the New Size

Re-run the original usage check:

df -h /

Expected output:

Filesystem Size Used Avail Use% Mounted on
/dev/mapper/ggrock--vg-root 17G 3.7G 12G 24% /

The Size column now reflects the successful increase.

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Updated on: 22/06/2026