Virtual memory for sytems with 16GB RAM

General system Kernel, boot, graphics & hardware
1

In couple occasions when I was capturing Firefox performance traces, Out-of-Memory terminated Firefox.
So, I consulted with Grok and I settled on the following memory configuration

  1. 16 GB RAM
  2. Zram will add a virtual compressed memory of up to additional 16GB
/systemd/zram-generator.conf
[zram0]
zram-size = min(ram * 0.85, 16384)
compression-algorithm = zstd
swap-priority = 100
  1. 64GB Swap file on SSD drive.

What is your memory setup if you have a 16GB RAM

2

I have 32G memory and I just have setup a 4th of my ram total for zram.

[zram0]
zram-size = ram / 4
compression-algorithm = zstd
fs-type = swap
swap-priority = 100
3

Why asking Grok? That is stupid. Ask us!

[zram0]
#zram-size = ram / 2
zram-size = 16384
compression-algorithm = zstd
swap-priority = 100
fs-type = swap

I have 64GB of physical Memory.

4

Since a while back, following one of the “innumerable” discussions on swap, zswap and zram, I decided to switch all my systems from zram to zswap (plus swapfile) mostly because it is already a kernel feature and well integrated into kernel’s own memory management.

On a system with 16G RAM and 16G swapfile (on SSD; I could do with less; this was set up when I still used hibernation and I haven’t bothered to change it), these are my current zswap parameters:


$ grep -r . /sys/module/zswap/parameters/
/sys/module/zswap/parameters/enabled:Y
/sys/module/zswap/parameters/shrinker_enabled:Y
/sys/module/zswap/parameters/max_pool_percent:30
/sys/module/zswap/parameters/compressor:lz4
/sys/module/zswap/parameters/accept_threshold_percent:80
5

Is this information absolutely necessary? Or rather, what does it improve?

Is it necessary to explicitly define the file system as well?

6

No.

the device will be formatted as swap, if neither fs-type= nor mount-point= are specified

7

I should ask you next time. But AI Agents are improving, and I cross-check their “advice” often