"Getting" more RAM

Table of Contents

Need more RAM?

We can get memory from the SSD and make it a RAM memory.

!!! Don’t install, READ FIRST !!!

Overview

Method 1: Swap file

Post installation is better, don’t need to mount anything and the creation is easy.

sudo dd if=/dev/zero of=/swapfile bs=1M count=17408 status=progress
  • dd: disk duplicator tool
    • if: input file (zeroed bytes).
    • specify a directory
  • of: output file path (must be under /
    • out put directory.
    • must to be under / (root)
  • bs: block size.
  • count: total MBs to allocate- binary GB to MB.
  • status: shows live progress during creation.

Permissions:

sudo chmod 600 /swapfile

sudo mkswap -U clear /swapfile

Activate:

sudo swapon /swapfile

Need to mount the swapfile:

sudo nvim /etc/fstab

add the path to swap file:

/swapfile none swap defaults 0 0

Method 2: Zram

zram, formerly called compcache, is a Linux kernel module for creating a compressed block device in RAM, i.e. a RAM disk with on-the-fly disk compression. The block device created with zram can then be used for swap or as a general-purpose RAM disk. The two most common uses for zram are for the storage of temporary files (/tmp) and as a swap device. Initially, zram had only the latter function, hence the original name “compcache” (“compressed cache”).

Install:

sudo pacman -S zram-generator

Create a config file: /etc/systemd/zram-generator.conf

[zram0]

zram-size = ram / 2

EOF

Save + Reboot to activate.

What to pick?

Best Practice:

Use ZRAM (6 GB) as fast, compressed memory.

  • Performance boost.
  • No SSD wear.
  • Great for apps, browser tabs, compiling, etc.

Use a Swap File (14–15 GB) as safety net.

  • Handles memory overflow.
  • Enables hibernation (optional).
  • Easy to resize or delete later.

Why?

ZRAM:

  • Stores more “virtual RAM” by compressing in real RAM.
  • Much faster than SSD.
  • Doesn’t wear down your SSD.
  • Ideal for active use (apps, multitasking, compiling).

Swap File

  • Only used after zram fills.
  • Protects from OOM (Out-of-Memory) crashes.
  • Optional for hibernation support.

The Plan:

As we seen above, i’m going to make with Zram with 6 GB and Swap-file method with 5 GB.

Zram

Install Zram:

sudo pacman -S zram-generator

Create the config file:

sudo nvim /etc/systemd/zram-generator.conf

zram-generator.conf

[zram0]
zram-size = ram / 2
compression-algorithm = zstd
Troubleshoot

If it’s fails, create in manually

sudo modprobe -r zram
sudo modprobe zram
echo 4G | sudo tee /sys/block/zram0/disksize
sudo mkswap /dev/zram0
sudo swapon /dev/zram0
swapon --show

Then, reboot.

Make the Swap-file:

Disable CoW:

sudo mkdir -p /var/swap
sudo chattr +C /var/swap

Make the file:

sudo dd if=/dev/zero of=/swapfile bs=1M count=16384 status=progress

Give the swap permissions:

sudo chmod 600 /swapfile

sudo mkswap /swapfile

sudo swapon /swapfile

Mount it:

echo '/swapfile none swap defaults 0 0' | sudo tee -a /etc/fstab

Check the new memory:

swapon --show
free -h

Results

|Memory Type|Size|Description|
|---|---|---|
|Physical RAM|~15 GB|Actual installed RAM chips|
|---|---|---|
|ZRAM Swap|e.g. 7.7 GB|Compressed swap in RAM (fast virtual swap)|
|---|---|---|
|Swap File|16 GB|Swap space on SSD (slower virtual swap)|