this post was submitted on 19 May 2026
42 points (100.0% liked)

Linux

66746 readers
1155 users here now

From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

Rules

Related Communities

Community icon by Alpár-Etele Méder, licensed under CC BY 3.0

founded 7 years ago
MODERATORS
 

I have been setting up Zram, Swap, Swappiness and EasyOOM daemon on 16gb ram boxes, or lower. Someone asked me about 32gb of ram, or more, and I'm unsure. Wondering if others have experimented with this!

all 42 comments
sorted by: hot top controversial new old
[–] HelloRoot@lemy.lol 18 points 2 months ago (1 children)
[–] kiol@discuss.online 5 points 2 months ago (1 children)
[–] mactan@lemmy.ml 3 points 2 months ago

been testing this quite a lot for star citizen which regularly sees 20-40 GB use. zram is the easiest solution to avoiding OOM Killer by a long shot. zswap was swapping over 100 GB to disk cumulative throughout the day and still oom killing the game

[–] Heavybell@lemmy.world 3 points 2 months ago

Yeah, I have 96gb and I still assign a zram swap, just in case. I also have a zram tmp, and a zram for my portage compilation dir (I use Gentoo). The latter gets the most use.

[–] PetteriPano@lemmy.world 2 points 2 months ago* (last edited 2 months ago) (1 children)

zram makes sense if you do not have swap.

zswap is probably enabled by default in most distros. It compresses cold pages on the fly so that they're ready to quickly get swapped in and out.

I do hit the swap partition occasionally on my 32GB systems.

It doesn't really kick in until you have proper pressure. I want my swap partition for hibernation, anyway.

[–] monovergent@lemmy.ml 1 points 2 months ago (2 children)

My workstation has 48 GB RAM with 50% allocation allowed to zram, no swap. It works just fine. Once I use up the majority of my RAM, it kicks in the same way it would on any other system with less RAM.

[–] motruck@lemmy.zip 2 points 2 months ago (1 children)

Not according to the chrisdown blog post above.

[–] monovergent@lemmy.ml 0 points 2 months ago (1 children)

What about it? I see it kicking in at least 10 GB before my RAM is full and I haven't noticed any fundamental differences between how zram works on my 48 GB workstation and my 8 GB devices. Maybe I've never had a workload that filled all 48 GB + extra zram capacity, but it's never given me an issue.

[–] motruck@lemmy.zip 2 points 2 months ago

Use zswap not zram.

[–] SoulKaribou@lemmy.ml 1 points 2 months ago (2 children)

Shouldn't total ram amount always be powers of 2 (forgot the reason exactly) ? It sounds like 32 +16 wouldn't be ideal ? I remember that from my early days, but maybe it has changed ?

[–] FleetwoodLinux@lemmy.zip 3 points 2 months ago

There are some 24GB sticks around, same with 48GB sticks

[–] monovergent@lemmy.ml 1 points 2 months ago

That is correct, IIRC, the mismatch does limit how much of it can run in dual-channel. Even if a single stick is natively 24 or 48 GB, there is additional strain on the memory controller. It is the way it is on my setup since I had planned an upgrade to a full 64 GB and was holding off until a good deal on the remaining 32 GB kit, which will never come unless the AI bubble bursts.

[–] Eggymatrix@sh.itjust.works -1 points 2 months ago (3 children)

Genuinely curious: what are you doing to be needing this?

I cannot think of any modern usecase for swap a part from hybernation

[–] kiol@discuss.online 5 points 2 months ago

I've been using lower ram machines lately, so made me curious about if people are using things like zram with 32gb+

[–] amorangi@lemmy.nz 5 points 2 months ago (1 children)

Local AI can chew it up. Wasn't able to run certain jobs on 64Gb until I switched to zswap.

[–] Eggymatrix@sh.itjust.works 1 points 2 months ago

What kind of token per second are you getting with your model partially on disk?

[–] Outsider9042@lemmy.world 2 points 2 months ago (1 children)

Compiling Librewollf with a sufficient number of jobs is a great way to eat up 32GB of RAM, and the some.

[–] Eggymatrix@sh.itjust.works 0 points 2 months ago (1 children)

Swapping will make it slower not faster, reduce jobs?

[–] Outsider9042@lemmy.world 0 points 2 months ago (1 children)

No. Most of the build jobs are fast and small. A couple take up gigabytes at a time. Swap is on SSD anyway. Its fast enough.

I also use NixOS and GuixSD. There are cases where binary caches haven't caught up with the package definition. Situations like Librewolf, LibreOffice and kernel all compiling at the same time.

Sure I could mess around with limiting jobs and build runners... Or I could just have swap, and never worry about it again.

Just a BTRFS swapfile. I'm not worried too much about performance. I rarely hit it and most of the time i don't even need it. Until I do.

[–] Eggymatrix@sh.itjust.works 1 points 2 months ago

Ok, you do you. In my experience that is not how that works, but there is an argument to not worry about it if it works well enough.

[–] ISO@lemmy.zip -2 points 2 months ago (3 children)

Why do you think 32GiB is special compared to 16GiB?
And wtf is EasyOOM?

You maximize the usefulness of zram by actually increasing sappiness, and giving zram devices high priority. e.g.

sysctl vm.swappiness=100

for i in {1..8}; do
  swapon /dev/zram${i} -p 32767
done

Then you enable other swap devices with lower priority.

This is the way regardless of how much RAM you have. I mean, it may be pointless if you never ever exceed, let's say 10/32GiB (including caching). But it still wouldn't be harmful in any way.

[–] non_burglar@lemmy.world 5 points 2 months ago* (last edited 2 months ago) (1 children)

That isn't how swappiness works.

Changing the sysctl for swappiness only adjusts the ratio of anonymous and file pages, it doesn't set a "threshold" or "aggressivity" in swapping pages, nor does it dictate how much or how little to swap.

It's generally ill-advised to touch swappiness at all unless you know what you're doing. You can start here.

If you're going to hand out free advice, at least make sure the advice is worth the price of admission.

[–] ISO@lemmy.zip -5 points 2 months ago (1 children)

If you’re going to hand out free advice, at least make sure the advice is worth the price of admission.

This is very ironic, considering your comment is a mix of straw man and wrong.

[–] floquant@lemmy.dbzer0.com 3 points 2 months ago

"a strawman is when people disagree with me!"

[–] kiol@discuss.online 2 points 2 months ago

I simply haven't had the chance to try it yet, so asking

[–] kiol@discuss.online 1 points 2 months ago (1 children)
[–] ISO@lemmy.zip -3 points 2 months ago

Oh, you wrote "easy" not "early" in OP. In any case, this looks stupid. But to each their own, I guess.