add swap file on the linux-install

well from time to time i install a new notebook and doing so i want to add swap file on the linux-install.

So here a little story: well my notebook (a old one) doesn’t have that much swap space and yes i really think the swap space is not adequate and much enough,

so i think i have to do something and to create swap file on my Linux notebook. a friend of mine told me that i can do even more - i can create multiple swap files as well he said.

well - it *allways helps me if i write down such steps *- so i can make sure if i have all steps together. And perhaps - if one tiny step is missing, feel free t add some lines - add a comment. Thank you in advance.

So here we start: this is the beginning

well i am trying to make up my mind how to create swap file on my Linux notebook. I am using a Ubuntu OS - so i guess that i have to test it on my ubuntu-notebook.

well i think that there are several preliminary steps do take - before i can set up a swap-file. the very very first step in the show:

we just** make a new swap file**

At the beginning i think that i ll have to create a file with the size of swap space Well let’s assume that I want to add 2 GB of swap space to my Notebook - and to the operating system.

I will go through the necessary steps - that means all the steps that are necessary to do a nicer and good little Swap-space-file.

So First things first: we do some preliminariy things:

at the very very beginning i think that i will have to use the so called fallocate command to create a file of size 2 GB. This is the command i have to add in the terminal:

sudo fallocate -l 2G /swapfile

well my girlfriend allways uses some of these commands when she is making a swapfile: the recommends me to allow only root to read and write to the swap file. So - to follow this recommendation (of my girlfriend) as she allways has good recommendations and i think it is a good thing i guess. We ll even see warning like “insecure permissions 0644, 0600 suggested” when we try to use this file for our new swap area (that we want to cr eate)

sudo chmod 600 /swapfile

Well to be frank We have to go further: what about the name of our tiny swap file!? btw: as mentioned above - yes it could be anything. If one needs more than one - if one needs
multiple swap spaces, he can give it any appropriate name

like so for example.

swapspace_file_a, swapsüace_file_b etc.
swapspace_file_c and so on and so forth

Well we see here:_ It’s just a file with a so called predefined size: that is pretty easy. And yes - i follow to the recommendation of my girlfriend.

That said we can go further in the story.

the next step is pretty important:

the filecreation-step 2: now we mark the new file as a so called swap space

Well at this point we need to tell the Linux system that our new file - (which w e have created now) that file will be used as a so called swap space: we can do that with mkswap tool.

sudo mkswap /swapfile

Well at this point we should be able to see an output like this:

Setting up swapspace version 1, size = 2048 MiB
and here we can do like so: use no label, UUID=xyz

and now - we can go ahead and do even more. We can do more in the step5

Step 3: the next step in the show: at this point we can do the good thing - and enable the swap file

With this step - our system knows that the file swapfile can be used as a so called swap space. And this is generally a good thing!

but wait: it is not done yet. We have to do even some steps more: that said - we ll need to enable the swap file so that our system can start using this file as swap. And believe me dear friend: this is a pretty important step We can not do the creation of the swap file without these preliminaries:

So the command here would be like the following command:

sudo swapon /swapfile

Now if we check the swap space, we should see that our Linux system recognizes and uses it as the swap area:

swapon --show
NAME TYPE SIZE USED PRIO
/swapfile file 2048M 0B -2

so we ll have to take care that the changes are pretty permanent on the system - that is on my tiny notebook; so in the next step i ll have to take care for this. We move ahead in the next step the Step 4 we do even more: now we make the changes permanent. And my girlfriend said to me that this is damned important. So i belive this.

This step seems to be important for me - since i thin that doing it will stop me form doing the same thing over and over - again and again: Well whatever we have done a swap-file-creation it is (first of all) is temporary file.

But - sure thing: we want more - at least i want to have so i think that we have to reboot the system and all the changes will disappear. And yes: this is not what we want.

We want to make the changes permanent by adding the newly created swap file to /etc/fstab file.

That said - i think that i t is allways a good thing if we do a (quick and dirty) backup before we make any changes to the /etc/fstab file.

sudo cp /etc/fstab bla bla bla bla /etc/fstab.back

Now we have came thus far - i am happy - and my girlfriend is happy too:

Now we can add the following line to the end of /etc/fstab file:

/swapfile none swap sw 0 0

Woooh - wooh - we came thus far.
Now it is necessary t o do a little step


echo '/swapfile none swap sw 0 0' |

and thus it is important to see that

sudo tee -a /etc/fstab

Now after all these many many i guess that we have everything in place. our swap file will be used even after we reboot the notebook. We have come thus fare - thats awesome: in the last step we have to adjust the so called swappiness

well the so called swappiness parameters determines how often the swap space should be used. My girlfriend says - it is this a pretty important thing. Well the so called swappiness value can be in the ranges from 0 (that is zero) to 120. Higher value means the swap space will be used even more often -that means even more frequently.

The default swappiness in Ubuntu desktop is about 50 : i guess while in server it is 1.

well - we can check the swappiness with the following command:

cat /proc/sys/vm/swappiness