Best practices for up/down sizing Linodes?
Hey everyone, as per the question, i'm wondering if there is any best practices for up/down sizing Linodes. Now I understand how this question may seem broad at first, so let me give you an example.
I was discussing this topic recently with a friend of mine when he mentioned that it is general rule of thumb to up-size your instance if you constantly hovering above ~80% usage of the resources you are using (CPU and/or RAM). Just wanted to know if there is any other general tips/practices like this.
Also, I am hosting an 8 vCPU instance and find myself hovering comfortably around 300% CPU usage. Would it be appropriate to down-size to a 4/6 vCPU instance (use case is CPU intensive so RAM is negligible) without experiencing any significant trade-offs?
Thanks in advance!
1 Reply
jdutton
Linode Staff
Hey Alan - this is a great question. While this is really a case-by-case situation, there are definitely a few things to keep in mind when considering an upgrade or downgrade of your server.
From personal experience, I tend to agree with your friend in that ~80% resource usage tends to be my benchmark as well. It's worth noting that regularly hovering around 80% adjusted CPU usage tends to be the threshold at which Linode will start to consider the usage excessive. This is around the point where you could be putting stress on your Linode's host machine or causing CPU steal for other shared users.
Disk space is a bit different. In general, it's never a great idea to max out your storage, as this can cause issues with applications running correctly, and it can even cause some services to crash or data to corrupt. That said, it's more or less just something to keep an eye on; I would recommend considering an upgrade around the 80-90% usage range.
*As an alternative to upgrading for storage reasons, you can always look into adding a Block Storage Volume to your Linode. You can even investigate the possibility of compressing/archiving files to free up space on your current disk.
If you find that your disk usage is suddenly really high, I would recommend checking out some of the troubleshooting steps in this other Community post, as there could be some other things going on:
Why is my Linode suddenly using 100% of its CPU?
In terms of your example, running around 300% on an 8 vCPU instance (300/800% available) is a really nice level. While downgrading to a 6 vCPU should also be fine (this would put you at 300/600%), I would be wary about going down to a 4 vCPU, as you would be approaching 75% adjusted CPU usage pretty quickly (300/400%). All that to say, if RAM isn't an issue, you shouldn't see too much of a degredation in performance downgrading to a 6 vCPU instance, but a 4 vCPU might be pushing it. :)
Just so that you have the necessary resource, here is the link to our guide on resizing your Linode:
Hope this answers your question!