Tag: power management

When Did I Last Reboot My Linux Box?

If you want to know when you did your last reboot on your Linux box, it’s actually pretty easy. This article explains how. I’m still not feeling quite up to snuff, so a quick and easy article is the call for the day!

You can run uptime in the terminal, and that will tell you how long your system has been up and running. The output will look something like this:

At this point, you could do the math and find your last reboot time. Of course, this being Linux, there’s an easier way to do this. This will be a quick (and easy) article and hopefully I’m doing a bit better tomorrow.

Find Last Reboot:

Like so many of these things, we need to start with the terminal open. You can do that by using your keyboard. Just press CTRL + ALT + T and your default terminal emulator should pop right up!

With that open, you can start with:

Which will give you an output similar to:

But, the command’s usefulness doesn’t stop there. No, no it does not! You can modify the command in a couple of ways to get some more refined response. Let’s say you only want the last three results? If so, you’d use this command:

This will give you an output like this:

You can also use ‘grep’ for your refining needs. Let’s say you want to know when you last rebooted in the month of May? Well, you can easily do that!

The output of which would look similar to this:

And, there you see it. As you can see, there were three reboots in the month of May on that box. This information may be useful for debugging reasons or even compliance reasons. How you use the information is up to you! Ain’t my job to tell you how.

Closure:

There. There’s your darned article for the day!

Seriously, yesterday’s article was really messed up. Fortunately, the kind folks at Reddit chimed in and were eager to help! The folks at Linux.org are usually good at catching the mistakes, of which there were many, but probably didn’t as the article is one from the old site and probably only skimmed it if they read it at all.

This leads me to think that I’m eventually going to have issues with getting an article up every other day. I’m still going to try, and I’ve done so since the start, but it’s pretty likely that I’ll eventually miss a day. I’ll try to take steps to not let that happen, but the real world is a fickle mistress.

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How To: Disable Sleep And Hibernation on Ubuntu Server

For some reason, Ubuntu Server comes with ‘power management’ enabled. This is an article that tells you how to disable sleep and hibernation in Ubuntu Server. It’ll work just fine for non-server installs, but this is aimed specifically at the Ubuntu Server release.

I recently was working on my own router. For this, I used Ubuntu Server as the base operating system. For some reason, it was shutting itself down after periods of inactivity. This isn’t acceptable behavior for a device that’s meant to be running all the time.

I checked in my logs and I found entries like this one:

Apr 3 12:18:27 server systemd[1]: Reached target Sleep.

That was entirely unacceptable. I do not know why power management was installed, nor do I know why it was active by default. I merely know that it was and that I couldn’t have that behavior with a server, a device meant to be always powered on.

So, I did what anyone would do in my shoes. I disabled sleep and hibernation entirely. It’s quick and easy – and effective! I’ll show you how!

Disable Sleep/Hiberation:

Like most articles, you’re gonna need a terminal. If it’s actually a server, you’re likely already able to connect with SSH. So, add the step of connecting to the server if you’re doing this remotely. If not, just proceed.

Once you have your terminal open, you’re to kill everything that has to do with suspend, sleep, or hybrid-sleep. It’s actually pretty easy. Start by opening said terminal, by pressing CTRL + ALT + T and then enter the following commands:

First, you mask ‘sleep.target‘:

Then mask ‘suspend.target‘:

And mask ‘hibernate.target‘:

Finally, mask ‘hybrid-sleep.target‘:

Later, should you change your mind, you can unmask them and that’ll enable them again. Just change ‘mask’ to ‘unmask’ and run the commands again. See? Pretty easy!

If you want, you can verify the efficacy. Simply use the following:

(You can change ‘sleep.target’ to one of the above services and check them individually.) 

Closure:

That’s it! I told you that it’d be pretty easy. It’s not only easy, it’s easy to undo this should you change your mind. Again, I do not know why power management is enabled by default in a server release. Nobody asked me! So, that’s how you disable sleep and hibernation with Ubuntu. (It’ll surely work with other distros.)

Thanks for reading! If you want to help, you can donate, write an article, vote for articles you like, share this article on social media, buy cheap hosting, register to help, etc… Nobody ever reads the last paragraph anyhow. Still, you can help if you want!

Update 01.27.2020 Per comment.

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