Why is my Linode using 100% disk storage?

When you look at your Linode's Disks/Configs tab, you are seeing the total amount of storage that is available for you to allocate to your disks based on the current plan your Linode is on. The percentage used is how much of your available storage you have allocated. It doesn't indicate the actual used space on the disk(s) themselves. To verify the actual used and free space on your server's disk, you can run the following command:

df -h

More information on Disks and Configuration Profiles can be found on the following page.
https://www.linode.com/docs/platform/disk-images/disk-images-and-configuration-profiles/

Having 100% of your allowed disc storage allocated is not a good idea. What are you going to do if you have to restore a backup or snapshot? Where's the restore going to go?

You really don't want to reset your system back to the last backup because you removed some important file do you?

-- sw

Good observation, @stevewi — this relates to our reasoning for our common recommendation that customers restore backups to new Linodes, rather than to the existing, backed up Linode.

Restoring backups to new Linodes have the added benefit of being less prone to config messes — I've seen plenty of issues arise from customers restoring to the same Linode, leaving the old disks, backing up both sets of disks, then having to untangle messes down the line.

Once you're confident in the integrity of the restored backup, you can simply swap IPv4 addresses (however, not an option for IPv6) and delete the original Linode.

@bbigger --

I only have about 25% of my available disc space allocated to images. Of that 25%, 98% is allocated to the root file system and 2% is allocated to swap.

Most people allocate WAAAAAAY more than they need for file system space (also way more than they need for swap). Also, since my Linode is fairly remote to where I live, I don't use X Windows, Gnome, KDE or any fancy visual environment (network latency too high) so that saves A LOT of disc space. I'm also pretty conscious of what I have installed. If it's not needed by a service my Linode provides, it's not installed.

I also use deborphan and other tools to look for unneeded/unused packages.

My Linode is the 4Gb mem/80Gb disc flavor.

I have enough free space to keep almost 3 backups of my root partition simultaneously.

-- sw

Gotcha — I see where you're coming from @stevewi. Really nice practices you have going to maximize the utility of resources made available from your Linode's plan.