[SOLVED] Virtual disk of 100 GB, but only 50 GB available?

[rogierl]

Hey, I have a virtual machine configured like this:



Now after installation of Ubuntu server on the guest, the df -h command gives me this:



So I'm wondering, where is the other 50 gb? I would expect a bit more free space after a (fresh) installation of Ubuntu server.

 

[Republicus]

Was the disk resized after the OS install?

 

[rogierl]

Was the disk resized after the OS install?

No, I created the VM, then installed Ubuntu server. Right after installation I ran "df -h".

 

[czechsys]

PVE lvm configuration != VM lvm configuration

 

[Dunuin]

Thats because of the new Ubuntu installer. PVE will create a 100GB virtual disk but the ubuntu will only use part of that by default if you don't manually tell the installer to use the full space. So you need to extend the VG, LV and filesystem inside the guest.

 

[rogierl]

PVE lvm configuration != VM lvm configuration

I know; but I still miss GBs then, right?
VM config is 100 GB
Then, after fresh install of Ubuntu server, I still have 41 GB free.... where are the other GBs?

(and how do I debug this?)

 

[rogierl]

Thats because of the new Ubuntu installer. PVE will create a 100GB virtual disk but the ubuntu will only use part of that by default if you don't manually tell the installer to use the full space. So you need to extend the VG, LV and filesystem inside the guest.

Aha!!! This explains!!! Let me try to create a test VM and take a screenshot. One moment...

 

[rogierl]

Here are the screenshots. In this case the VM config in Proxmox has a 100 GB disk. For some reason the installer doesn't "claim" all that disk space, right? Can you elaborate a bit more? (sorry, still learning here...)

 

[Dunuin]

The pictures show you that you got a 100GB disk. Ubuntu will create 3 partitions. 1MB for the grub bootloader, 1GB for the boot partition and 98,997GB as a PV (physical volume) for your LVM. On top of this 98,997GB PV is a 98.996GB VG (volume group). But on top of that there is only a 49,498GB LV (logical volume) for your root. So half of your VG is unused and ubuntu only uses that 49,498GB LV. So you only got 49,498GB of usable space unless you create your own LV using that unallocated space or extend that existing LV to use all the space. Or tell the installer to create a LV that should use the full 98.996GB of the full VG size.
You really should read a bit on how LVM works.

 

[rogierl]

The pictures show you that you got a 100GB disk. Ubuntu will create 3 partitions. 1MB for the grub bootloader, 1GB for the boot partition and 98,997GB as a PV (physical volume) for your LVM. On top of this 98,997GB PV is a 98.996GB VG (volume group). But on top of that there is only a 49,498GB LV (logical volume) for your root. So half of your VG is unused and ubuntu only uses that 49,498GB LV. So you only got 49,498GB of usable space unless you create your own LV using that unallocated space or extend that existing LV to use all the space. Or tell the installer to create a LV that should use the full 98.996GB of the full VG size.
You really should read a bit on how LVM works.

What would be the reason for the installer to tell LVM to not use the full capacity?

 

[Dunuin]

I don't know. But LVM snapshots would be for example a reason not to allocate all space, because snapshots will use this unallocated VG space.

 

[rogierl]

Here more info: https://askubuntu.com/questions/126...-disk-space-was-allocated-during-installation

 

[rogierl]

Found out that the installer by-default ticks this "" setting.
I don't need (and want) that for my home-server VMs.
Un-ticking gives me the full available disk space (as configured in Proxmox)