Ever found yourself running out of disk space on your Linux system? Well, grab a coffee and let me tell you about my recent adventure extending a logical volume using LVM (Logical Volume Management). It’s less scary than it sounds, I promise!

The Initial Problem

Our story begins with a simple df -h command that revealed my system was running low on space. The volume group /dev/vg/sys was nearly full, and it was time for some disk magic.

Step 1: Expanding the Physical Disk

First, I needed to expand the underlying physical disk. In my case, I was working with a VMware virtual disk that needed to be increased from around 59GB to 69.8GB. This was done through the virtualization platform.

Step 2: Updating the Partition Table

After expanding the virtual disk, I ran into an interesting challenge – overlapping partitions! This is a crucial detail that could trip up many administrators. Here’s how I handled it:

1. First, I checked the current partition layout:

lsblk

This showed me that sda5 was a logical partition within the extended partition sda2.

2. I attempted to resize partition 5 directly:

parted /dev/sda resizepart 5

But got an error about overlapping partitions. Oops! This makes sense because we need to handle the extended partition (sda2) first!(see the image below)

3. So, I resized the extended partition (sda2) first:

parted /dev/sda resizepart 2
End? [59.1GB]? 69.8GB

4. Only then could I successfully resize partition 5:

parted /dev/sda resizepart 5
End? [59.1GB]? 69.8GB

Pro tip: When dealing with logical partitions (like sda5) within an extended partition (sda2), always resize the extended partition first!

Step 3: Physical Volume Resize

Now that we’ve resized the partition, we need to tell LVM about the new space. This is done using the pvresize command:

pvresize /dev/sda5

This command updates the physical volume to recognize the newly available space. Magic!

Step 4: Extending the Logical Volume

Here’s where my first attempt went sideways. I tried:

lvextend -l +100%FREE /dev/vg/sys

But got an error about invalid arguments. Learning from my mistakes, I switched to using -L instead:

lvextend -L +10G /dev/vg/sys

Success! The system reported:
“Size of logical volume vg/sys changed from <53.14 GiB (13603 extents) to <63.14 GiB (16163 extents).”

Step 5: Filesystem Resize

Finally, the last step is to resize the filesystem to use the newly available space:

resize2fs /dev/vg/sys

This step is crucial – without it, your filesystem won’t be able to use the new space even though the logical volume has been extended.

Verification

To confirm everything worked as expected, I ran:

df -h 

And voilà! The output showed my newly expanded filesystem with 21G available space, up from the original capacity.

Tips for the Brave

• Always backup: Before attempting any disk operations, make sure you have good backups
• Handle partition hierarchy: Remember to resize extended partitions before their logical partitions
• Follow the LVM chain: Physical disk → Partition → Physical Volume → Logical Volume → Filesystem
• Keep commands handy: Save these commands somewhere safe – you’ll probably need them again!

Conclusion

LVM might seem intimidating at first, but it’s actually a powerful tool that makes disk management much more flexible. Just remember to take it step by step, and always verify your commands before hitting enter. And most importantly – don’t forget about those partition hierarchies!

Remember, in the world of system administration, patience is not just a virtue – it’s a requirement!

Happy disk extending!