Running out of Disk Space

It has reached a point where the disk usage of a Digital Ocean droplet has reached 69.4% of 19.56Gb.

running out of disk space.png

I know that the total number of applications I use is broadly 2Gb - so what is using up all that disk space?

It took a while to learn some useful linux commands to investigate. A good resource describing tools to monitor server resources at Digital Ocean.

The most useful command for my investigation shows the usage of folders:

sudo du -h  --max-depth 1

sudo du max depth 1.png sudo du lib.png sudo du modules.png too many old unused kernels.png

As you can see in the /lib/modules folder, there were many old kernel versions taking a total of 5.8Gb.

I verified the currently running kernel using

uname -r

I was running linux-image-3.13.0-37-generic - that was an old one….so wanted to use the latest.

Use the latest Ubuntu kernel through Digital Ocean Control Panel

This is a great article on Digital Ocean to show how to change the kernel that is used by your server droplet. I was not aware of needing to do this so was pleased to find the instructions

how to update a digitalocean server kernel

After following the instructions to change the kernel through the DigitalOcean Control Panel I powered off the droplet.

sudo poweroff

Note that whilst my droplet was powered off, I took the opportunity to take a snapshot Image. This also restarts the droplet once the image is taken. The droplet kernel was now updated.

digital ocean droplet now running newer version.png

Delete old Kernels using sudo apt-get remove

As I am using a service from Serverpilot.io, which is a simple management system for DigitalOcean servers, I contacted them and received this confirmation regarding deleting old kernels:

Justin Samuel (ServerPilot Support) Feb 4, 13:55 Hi Hywel, You’re welcome to remove any kernel versions you don’t intend to use again. What you should check before removing any version is that: 1) It isn’t the most recent kernel version installed. 2) It isn’t the same kernel version that’s currently running according to uname -r 3) It isn’t the kernel you have selected in your server settings in DigitalOcean. You can then remove a specific kernel with this command: sudo apt-get remove linux-image-X.Y.Z-XX-generic

sudo apt get remove.png

sudo apt get remove continue.png

Delete old Kernels using sudo apt-get autoremove

The above method though good, still did not remove all the redundant packages and dependencies. It would also be slow and tedious.

Further reading, I found the following useful link RemoveOldKernels which describes the use of sudo apt-get autoremove:

The system keeps track of which kernels are older and marks them eligible for removal using this method. Most users should run autoremove every few months or so. Systems with a separate /boot partition should run autoremove every two-four weeks. Mark your calendar, make it a routine. Autoremove can be run as often as you like - running it more often will not harm your system

sudo apt-get autoremove

sudo apt get auto remove continue.png

According to sudo apt-get autoremove, I cold free up over 7Gb…..here goes…

sudo du after removing old files.png

system information after.png

The disk usage of a Digital Ocean droplet is now 20.5% of 19.56Gb. That has reduced the disk usage by almost 50%..I’d say a success.