20gb ram, 10gb zram, 10gb swap, default values. What should I change?
20gb ram, 10gb zram, 10gb swap, default values. What should I change?
I assume I should get rid of most of the swap. I also read somewhere to increase... swappiness of zram?
Odd consideration, but... I use 16Gb of ram and I have zero swap space and I've never seen a freeze in the three years this system has been assembled.
It could just be the way I tend to use my PC, light photo manipulation, some audio editing, some gaming just not AAA. I'm never stressing my system unless I'm opening a compressed file or rendering a video.
Odd consideration, but... I use 16Gb of ram and I have zero swap space and I've never seen a freeze in the three years this system has been assembled.
You won't see big problems until you use most of the ram, then you're toast. Also Linux (if that's what you're using) prefers to have more cache at the expense of swapping out pages. There's a lot of rarely used code on many apps that can be safely swapped out to get you more cache.
I used a work laptop without swap for a while and it was very anoying. RAM intensive tasks were Rust IDE integration and compilation, data engineering, ...
Exactly the same for me, 26Hb, no Swap installed, never had a freeze or a problem in the two years using Arch
Those defaults sound pretty sensible. I have as much swap as I have RAM because I set things up to hibernate. I believe pop os has the swappiness set to 180 for using the zram.
Should I lower swap? How do I change the swappiness?
Have a look at this for info on swappiness. As for your swap, if it's not causing you problems, it can't hurt to have it.
There's some instructions here but basically:
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sudo apt install zram-config -
append to end of
/etc/sysctl.conf:vm.swappiness = 180 # disable swap readahead (since using zram swap) vm.page-cluster = 0Can check these have been applied with
cat /proc/sys/vm/page-clusteror.../swappiness
-
If you have more than enough RAM isn't the older suggested configuration of low swappiness + modest swap should be more performant than encouraging the system to swap more and paying the price of compression. EG if you are apt to use 8GB in normal usage 32-64GB are at this point relatively inexpensive.
Why would you get rid of the swap? Having swap space should never hurt. Swap can sit empty when it's not needed, and some memory pages are rarely used, so you'll hardly notice if they're swapped out.
Only too much swapping is annoying/slow. This happens if you run out of physical RAM; mostly independent of your swap size.
You can listen to the experts here for how to fine-tune the parameters (swappiness). Linux (as most operations systems) is built with the assumption that swap > physical RAM exists. Linux can run without swap, but the kernel runs into a huge problem if RAM becomes nearly full and has to kill processes. Usually adding swap is the better option.
You know, for some reason I thought that zram was on the disk, and it isn't. That makes a huge difference. I'll keep the swap then!
Zram usually has a very high compression ratio - around 4:1 for lz4 and 6:1 for zstd. You can set zram to 40-50 GB. It will still use less than 1/2 of your ram.
Zram has an option to write poorly compressible data to the disk instead of storing it in the ram. I would split the swap partition - 3 GB for zram writeback and rest for ordinary swap.
Oh, I think I might have thought zram was similar to swap, I didn't realize it takes up ram. Is there a way to see how much ram it's using? What do you think I should set my zram amount to(and how do I change the zram amount, I'm using zram-config)
Zram is basically a compressed swap device located in your ram. You can check the usage by running zramctl.
I would recommend setting mem_limit to 10 GB or disk_size to 40GB and algorithm to lz4.