"Regular" Ubuntu setup would look like this:
┌────────────────────────────────────────────────────────┐
│ The virtual drive │
│ ┌────────┐ ┌───────────────────────────────────────┐ │
│ │ │ │ OS partition │ │
│ │ │ │ ┌───────────────────────────────────┐ │ │
│ │ some │ │ │ │ │ │
│ │ boot │ │ │ root filesystem │ │ │
│ │ parti- │ │ │ │ │ │
│ │ tions │ │ └───────────────────────────────────┘ │ │
│ │ │ │ │ │
│ └────────┘ └───────────────────────────────────────┘ │
│ │
└────────────────────────────────────────────────────────┘
The usual mistake here is resizing the drive, but forgetting to resize the partition, so there's empty space after the partition but the partition (and by extension the filesystem within it) are still the same, old size. You did well by avoiding this one.
A variant of this is resizing the drive and the partition, but not the filesystem inside. GParted and similar tools do this automatically, but some users choose to delete the partition using more advanced tools (fdisk
, gdisk
, parted
, …), then recreate it, and forget that the filesystem doesn't grow automatically to fill the partition.
In your case you have a setup with LVM. Desktop Ubuntu uses this when instructed or when you choose to enable full disk encryption. I wouldn't be surprised if this was the default for Ubuntu Server. LVM adds another layer of abstraction that gives you slightly more flexibility when distributing disk space between multiple partitions.
┌────────────────────────────────────────────────────────────────┐
│ The virtual drive │
│ ┌────────┐ ┌─────────────────────────────────────────────────┐ │
│ │ │ │ Partition │ │
│ │ │ │ ┌─────────────────────────────────────────────┐ │ │
│ │ │ │ │ LVM volume group │ │ │
│ │ │ │ │ │ │ │
│ │ │ │ │ ┌───────────────────────────────────────┐ │ │ │
│ │ │ │ │ │ OS volume │ │ │ │
│ │ │ │ │ │ ┌───────────────────────────────────┐ │ │ │ │
│ │ some │ │ │ │ │ │ │ │ │ │
│ │ boot │ │ │ │ │ root filesystem │ │ │ │ │
│ │ parti- │ │ │ │ │ │ │ │ │ │
│ │ tions │ │ │ │ └───────────────────────────────────┘ │ │ │ │
│ │ │ │ │ │ │ │ │ │
│ │ │ │ │ └───────────────────────────────────────┘ │ │ │
│ │ │ │ │ │ │ │
│ │ │ │ └─────────────────────────────────────────────┘ │ │
│ │ │ │ │ │
│ └────────┘ └─────────────────────────────────────────────────┘ │
│ │
└────────────────────────────────────────────────────────────────┘
You have resized the disk, the partition and the volume group, but the volume inside it and its filesystem are still the old size.
Switch to the volume group using the dropdown in the top right corner of GParted's window. If you don't see it there, you need a newer version of GParted. The one included on Ubuntu Desktop 22.04 live media should work. GRML works too, I think.
Then you'll see what's inside the volume group and you should be able to grow the partition. As I've mentioned earlier, GParted will resize the filesystem for you automatically.