Linux Swap Size
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How Much Linux Swap Size Should You Need? – Easy

People get confused when it comes to Linux Swap. Many questions may arise in your head.

  • What is Linux Swap? What is it used for?
  • How much Linux Swap size should I need?
  • I have plenty of RAM on my system. Should I need Linux Swap?
  • And lots more other questions.

These are the most frequently asked questions when choosing Linux Swap size. But no matter what swap size you choose, it is always recommended to have a Linux Swap. It will help you in the long run.

What Is Linux Swap?

Computers use RAM (Random Access Memory) to run applications. More running applications need more RAM to operate. A computer with 1 GB or less RAM is not capable enough to do many tasks simultaneously. If you consider the modern work case scenario, any computer that has less than 4GB of RAM, will suffer from memory shortage. In this case, swap memory comes into play.

Swap memory is a breather to your computer when your system memory (RAM) is exhausted. During a Linux installation, it will use a small amount of your storage as a swap partition or swap file. This swap partition or file will act as RAM when you run out of system memory.

That means, adding more swap memory will increase performance, right? WRONG!

Look, adding more swap memory will not benefit you at all. Swap memory will only be used when it is needed.

When Is Swap Used In Linux?

Random Access Memory (aka RAM) is required to run every application. Swap on the other hand acts like RAM when the system memory is exhausted. As long as your system memory is available, chances are your swap memory is not being used.

But it depends on the swappiness of your system. If you set the swappiness value to aggressive, your system will thrash processes to the swap memory. Aggressive swappiness will help you free your RAM but also degrade performance by swapping out processes.

You need a balance between these two. The default swappiness value is 60 in most of the Linux distributions. But you can change it according to your need from 0 to 100. 0 will disable swappiness and 1 is the minimum value. 100 will swap out processes too aggressively and degrade the performance. The recommended value is 10 if you want to use most of your RAM and swap when necessary. But it will always depend on your workload.

When the RAM hits the swappiness value, the kernel starts swapping out idle processes to free up the RAM. This will increase performance and give you room to complete memory-hungry tasks without crashing. When you need the idle process, the kernel will swap the process back into the RAM.

Do You Need Swap For Your Linux System?

It is a simple question with a complicated answer. As far as we know, having a swap partition will benefit the overall system performance, but it is not mandatory. If your computer has 32 GB or more RAM, you may not need any swap unless you use hibernation. Storages like HDD and SSD are cheaper nowadays, so why not have some swap space. It will not cost much and your computer will have some extra room to handle unwanted memory consumption.

How Much Linux Swap Size Should Be?

Now coming to the main question. How much Linux Swap Size should you use?

And the answer is, that there is no definite answer to this question. There are just recommendations, different thoughts, and opinions from different people.

Even the major Linux distributions like RedHat, Fedora, CentOS, and Ubuntu do not carry similar rules. They all have different work cases and different opinions.

RedHat suggests that having an amount of 20% of the RAM as Swap is a good idea.

Fedora has a different opinion on the swap size. It suggests swap size to be:

  • 2x of RAM if RAM is less than 2 GB (i.e. 4GB of swap for 2GB of RAM)
  • Size of RAM + 2 GB, if RAM size is more than 2 GB (i.e. 5GB of swap for 3GB of RAM)

Ubuntu on the other hand has a completely different approach as it considers hibernation. If you need hibernation, a swap size equal to RAM size becomes necessary for Ubuntu.

Otherwise, Ubunut’s recommendations are:

  • If RAM < 1GB Then Swap Size = RAM Size, Maximum Swap Size = 2X of RAM Size
  • If RAM > 1GB Then Swap Size (Without Hibernation) = √RAM or Swap Size (With Hibernation) = RAM Size + √RAM, Maximum Swap Size = 2X of RAM Size

I know what are you thinking. It is confusing. Maybe the table below will help you out.

RAM   No hibernation    With Hibernation  Maximum
256MB          256MB               512MB    512MB 
512MB          512MB              1024MB   1024MB
1024MB        1024MB              2048MB   2048MB

RAM   No hibernation    With Hibernation  Maximum
1GB              1GB                 2GB      2GB
2GB              1GB                 3GB      4GB
3GB              2GB                 5GB      6GB
4GB              2GB                 6GB      8GB
5GB              2GB                 7GB     10GB
6GB              2GB                 8GB     12GB
8GB              3GB                11GB     16GB
12GB             3GB                15GB     24GB
16GB             4GB                20GB     32GB
24GB             5GB                29GB     48GB
32GB             6GB                38GB     64GB
64GB             8GB                72GB    128GB
128GB            11GB              139GB    256GB
256GB            16GB              272GB    512GB
512GB            23GB              535GB      1TB
1TB              32GB             1056GB      2TB
2TB              46GB             2094GB      4TB
4TB              64GB             4160GB      8TB
8TB              91GB             8283GB     16TB

Can You Use Linux Without Swap?

Yes, you can use Linux without a swap partition or file. But why bother having a small amount of space as a swap? Storages are cheap now and allocating some space as a swap won’t hurt much. Hence it will increase the performance and help you tackle memory leaks. You may not need a swap partition if you have a large amount of RAM.

But if you have an older computer with 4GB of RAM or less, it will be beneficial if you use swap. It will give an extra layer of stability.

Does Linux Swap Size Matter?

This is a complicated question as it completely depends on a user’s workload. If you consider hibernation, the swap size should be equal to or higher than the RAM size. And if you don’t use hibernation, you can go either without a swap partition or use the table above as a reference to match your needs. But my recommendation is, that you should have a swap at least the size of your RAM. This will help you in the long run.

Conclusion

I hope you understand the concept of Linux Swap Size. You will find people who use and don’t use Linux Swap and both have their own opinions. But at the end of the day, you need to decide whether to go with a swap or without a swap depending on your workload. If you have a large amount of RAM (i.e 32GB or more), you may not need a swap partition. But if you have 4GB or 8GB of RAM, then I will recommend having a swap partition.

How much Linux Swap Size do you use? Let me know in the comment section below.

Published by MUHAMMAD SAFAYAT

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A general user who loves to play with Linux. He is a lazy person and spends most of his time watching Youtube videos. But He is passionate about Linux and FOSS (Free and Open-source Software). He tries different Linux distributions and open-source software to give his opinion and also share knowledge.

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