Should I increase swap file (ZRAM) and if so, how?

[Nooneeverasked]

I have 32GB RAM. When I created a W11 VM, and assigned 20GB to the VM, Aurora ran to 97% RAM usage and froze. I saw ZRAM is set by default to 8GB and I wonder if I should increase that? (I realize I also should decrease my RAM usage and what I give the VM)

I'm a noob, but found in a Kionite forum, the ZRAM generator is here: /usr/lib/systemd/
But the file itself notes to only use 8GB or less. I tried to change the number, but couldn't save the file.

Before I do something stupid, I thought I ask here :-)

Is 8GB swap file size enough? Is there a separate swap file besides what looks like an 8GB ZRAM drive? It seems ZRAM and swap file are terms used interchangeably, but they seem to differ. I keep reading 8GB is enough.

I read Linux deals with low RAM less gracefully than Windows (out-of-memory - OOM). I just want to make sure it uses more SSD if needed.

And before I forget, thanks so much for creating this OS! This is the best distro out of close to 30 I tested. Everything just works and I have literally nothing to fix or repair or maintain. Really boring (in a good way)

[Nooneeverasked]

It seems ZRAM isn't; actually SSD swap (it is called " Linuxswap" in the partition manager, though) . It is RAM that stored compressed data from RAM. We basically gain some " virtual" RAM at the expense of CPU power. Swapping from fast un-compressed RAM to still fast compressed RAM. This also explains why it can't be larger. it basically is a first stage of swapping before the SSD is used.

With that I need to re-phrase my question:
Do we still have a regular swap file? I read it would be in /var, but I can't see anything swap there. And is there a way to increase the SSD swap? Or is my original problem (freezing when 97% RAM was used) not related to this at all?

[renner0e]

I'm a noob, but found in a Kionite forum, the ZRAM generator is here: /usr/lib/systemd/
But the file itself notes to only use 8GB or less. I tried to change the number, but couldn't save the file.

The correct way is to override the file with sudo systemctl edit systemd-zram-setup@zram0.service. This will create a drop-in override in /etc, /usr does not need to be writable for this. This is the best practice on all systems.

Is 8GB swap file size enough? Is there a separate swap file besides what looks like an 8GB ZRAM drive? It seems ZRAM and swap file are terms used interchangeably, but they seem to differ. I keep reading 8GB is enough.

You can read more about this here:
https://fedoraproject.org/wiki/Changes/SwapOnZRAM

I guess you can try this change here, you need to create /etc/systemd/zram-generator.conf.

Do we still have a regular swap file?

No. You can create one I guess. https://wiki.archlinux.org/title/Btrfs#Swap_file use /var/swapfile instead.

[Nooneeverasked]

Thanks for the reply. I will leave it as is for now. If I use VM again, I assign less RAM. Maybe it is better to boot into W11 if i need to use Windows apps.

I read more about this. And it seems only newer distros use ZRAM. Older ones use a swap file. There are very few recommendations to use both. But I also read, using both ZRAM and swap file is bad.

I understand ZRAM is faster than a swapfile on SSD. But I wonder if using a swap file in addition (just in case) has a downside? I realize SSD is slower than ZRAM. But if SSD will be used, after all ZRAM is exhausted, that still should be better than a frozen OS.

This is just for my curiosity.