FAQ’s – Frequently Asked Questions

Last updated - Oct 30, 2021

  • Is it safe?

    Is SSH safe? Because that is what we are using to connect to your server. We are using the best in class ed25519 keys, not a low bit RSA key. After we've establish a connection we run ONE command, and that is `df`. That command has been around since 1971 and is present on all Unix based systems. We didn't stop there. The snippet we are giving you enables a feature called 'forced command' in SSH. This allows the public key to ONLY execute the specified command after which the connection is immediately terminated.

  • Why do you think it is safer than the altertives?

    All the other solutions require you to install software. That increases your attack surface. There have been numorous examples in which NPM packages are compromised. Even 'fail2ban' issued a CVE last year! Installing additional software is a hazzard but it get worse because you need to update it too. Sure, there's 'unattended-upgrades', yet an other thing to install and don't forget these reboots! Last but not least; when you need to pull data from the monitored server you need to expose an additional port. Less ports open is always better.

  • What are the altertives anyway?

    Popular at the moment are Graphana and to a lesser extent Telegraph from InfluxDB. Venerable solutions are Zabbix and Nagios. Slightly newer is Icinga and a recent entrant is NetData.

  • Can I cancel my subscription at any time?

    I dislike subscriptions as much as the next guy. Yes you can cancel any time.

  • Is there a discount when paid annually?


  • What happens if I don’t renew my license?

    When that happens monitoring of all but one of your servers will stop. Once you inevitably see that you have made a mistake and sign up again, monitoring will resume.

  • What kind of payment methods do you provide?

    Anything Stripe offers. Plus Bitcoin. Email me when you want to do that.

What is Disk Notifier

Last updated - Oct 30, 2021

  • What is Disk Notifier?

    A service which alerts you when you are about to run out of disk space. Thus preventing downtime and costing you stress and money.

  • What isn't Disk Notifier?

    Disk Notifier isn't for you if you need a whole lot of cool looking graphs. We focus on the bare minimum.

  • Why did you start Disk Notifier?

    A project of mine to scratch my own itch. In my career as a software developer I've seen some nasty incidents where a server went down. It was always a full disk. This is easy to prevent in principle, it just never happens. As a developer you are always late or busy. Monitoring and let alone alerting is just not something you have time for. That's why Disk Notifier. Dead simple disk monitoring.

  • What technology is Disk Notifier using?

    We are using a Rails backend with several, pardon the word, micro services. These are writting in Crystal. The static sales website is written with Hugo. Our database is the venerable Postgres and we use Redis as a message bus. The micro services run on a dedicated machine and the sales website runs on Netlify. The Rails backend runs on Render.com.

  • What architecture is Disk Notifier using?

    How is this even relevant?

  • Who's behind Disk Notifier?

    Harm Aarts. A pretty good developer.

  • How long do you plan do be running Disk Notifier?

    For a long time actually. I want this to stick.

Get started

Last updated - Oct 30, 2021

  • How do I create an account?

    You really have to ask?

  • I have a server, how do I let Disk Notifier know about it?

    Go to the 'Servers' tab when you are logged in. Enter the following info:

    • Host: The IP address or the domain name of your server.
    • Remote user: The user you allow us to log in with. This can be a dedicated user you created for this purpose or an exsisting one.
    • Port: The port SSH is running on. Usually '22'.
  • How do I add Disk Notifiers key to my server?

    Easy. Once you added your server on Disk Notifier you get a small snippet from us. That snippet includes a forced command, a public key and a comment. You need to add this snippet to your ~/.ssh/authorized_keys. That is it.

  • How do I revoke access to my server?

    Delete the line containing our public key in the ~/.ssh/authorized_keys file.

  • I want to receive alerts on Telegram. How do I do that?

    Log in and go to your users Settings. There you'll find a short instruction on how to link with our Telegram bot.

  • How do I suspend monitoring?

    At the moment? You don't. Delete your server. Or remove the public key on your server, you can add it back later.

  • How often do you check the disks?

    Every two hours our software logs in to your server and checks the disks.

Payments FAQ’s

Last updated - June 30, 2020

  • How much does Disk Notifier cost?

    Check out the pricing page.

  • Can I get a discount?

    Yes, if you pay yearly.

  • What are the differnces between the Noodle Shop and Mega Corp plans?

    The only difference is the number of servers we monitor for you. And I'm more inclined to respond to email from paying customers.

  • Can I cancel my subscription at any time?


  • What happens if I don’t renew my subscription?

    We suspend monitoring of all but one of your servers.

  • What kind of payment methods do you provide?

    Everything Stripe support and Bitcoin. Please email me if you want to pay with the latter.