Simple Linux Swap File Creation

[black3dynamite]

@scottalanmiller said in Simple Linux Swap File Creation:

A simple process for making a swapfile to add swap space to a Linux instance.

sudo fallocate -l 2G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
sudo echo "/swapfile swap swap defaults 0 0">>/etc/fstab

Or to copypasta as a single line:

fallocate -l 2G /swapfile && chmod 600 /swapfile && mkswap /swapfile && swapon /swapfile  && echo "/swapfile swap swap defaults 0 0">>/etc/fstab

sudo swapon /swapfile wasn't working for me. In /var/log/messages, I was getting these messages.

This works for me:

sudo dd if=/dev/zero of=/swapfile count=2048 bs=1MiB
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
sudo echo "/swapfile swap swap defaults 0 0">>/etc/fstab

[jmoore]

@scottalanmiller I think I did something similar a few months back to increase performance. Not sure it did much but I guess it hasn't hurt

[scottalanmiller]

@jmoore said in Simple Linux Swap File Creation:

@scottalanmiller I think I did something similar a few months back to increase performance. Not sure it did much but I guess it hasn't hurt

It reduces performance, but increases capacity.

[dafyre]

@scottalanmiller said in Simple Linux Swap File Creation:

@jmoore said in Simple Linux Swap File Creation:

@scottalanmiller I think I did something similar a few months back to increase performance. Not sure it did much but I guess it hasn't hurt

It reduces performance, but increases capacity.

Does using a swapfile vs a swap partition reduce performance to the point it is significantly noticeable?

[scottalanmiller]

@dafyre said in Simple Linux Swap File Creation:

@scottalanmiller said in Simple Linux Swap File Creation:

@jmoore said in Simple Linux Swap File Creation:

@scottalanmiller I think I did something similar a few months back to increase performance. Not sure it did much but I guess it hasn't hurt

It reduces performance, but increases capacity.

Does using a swapfile vs a swap partition reduce performance to the point it is significantly noticeable?

No, that's why it's done now. Swap should be used SO little, and flexibility trumps the tiny performance increase.

[jmoore]

@scottalanmiller Well that explains it lol. It was a long time ago now so don't remember what my logic was, or if there was any at all

[JaredBusch]

Just manually installed CentOS 8 for the first time on my local system to test something, and they still use a swap partition by default.

Warns you if you delete it.

[black3dynamite]

@JaredBusch said in Simple Linux Swap File Creation:

Just manually installed CentOS 8 for the first time on my local system to test something, and they still use a swap partition by default.

Warns you if you delete it.

I automatically ignore Fedora and CentOS warning about that.

[black3dynamite]

@black3dynamite said in Simple Linux Swap File Creation:

@JaredBusch said in Simple Linux Swap File Creation:

Just manually installed CentOS 8 for the first time on my local system to test something, and they still use a swap partition by default.

Warns you if you delete it.

I ignore Fedora and CentOS warning about that.

[JaredBusch]

@black3dynamite said in Simple Linux Swap File Creation:

I automatically ignore Fedora and CentOS warning about that.

I ignored it also. just pointing out the default behavior.