One of the servers I’m working with started running out of disk space recently. The machine is running on a Ubuntu VM in Windows, about 200 miles from my desk. I have remote access to the VM, but I don’t have access to the virtualization software. After requesting a disk resize through the IT company that manages our Windows network, here’s what I saw:

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root@outlays:~# df -h
Filesystem                Size  Used Avail Use% Mounted on
/dev/mapper/outlays-root   14G   14G    0G 100% /
...

The request I made was to increase the disk space from 14G to ~40G. That additional space doesn’t show up, as it’s free space on the disk (it hasn’t yet been assigned to a volume). Running the vgdisplay will show the additional space (Free PE / Size):

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root@outlays:~# vgdisplay
  --- Volume group ---
  VG Name               outlays
  ...
  VG Size               39.76 GiB
  Free  PE / Size       6412 / 25.05 GiB

So, the disk was expanded, however I needed to assign that free space to /dev/mapper/outlays-root … I wasn’t sure how. A bit of Googling brought me to this article: Extending LVM disks in Linux using VMWare virtual disks. The solution seemed to be to extend the /dev/mapper/outlays-root by the amount of freespace available in the volume group. First, I wanted to check out the /dev/mapper/outlays-root disk:

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root@outlays:~# parted
(parted) print all
...
Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/outlays-root: 14GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
...

And running the lvdisplay command shows the following:

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root@outlays:~# lvdisplay
  --- Logical volume ---
  LV Name                /dev/outlays/root
  VG Name                outlays
  ...
  LV Size                14 GiB

So, the assumption I made here was the /dev/mapper/outlays-root maps to /dev/outlays/root. Alright, I needed to expand /dev/outlays/root. Expanding the disk was as simple as running the following commands:

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lvextend -L+25G /dev/outlays/root

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resize2fs /dev/outlays/root

Now, here’s the amount of disk space I have:

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root@outlays:~# df -h
Filesystem                Size  Used Avail Use% Mounted on
/dev/mapper/outlays-root   39G  8.7G   28G  24% /
...

Much better.