On 1/16/22 15:03, John Mellor wrote:
On 2022-01-16 11:53 a.m., Grumpey wrote:
Um, I did not know I set up zram? How did that happen. Is zram now part of the basic Fedora install?
It has been a while my using zram. How do I disable it for now? With 16GB real memory and 16GB real swap partition, I want to see how things are working...
thanks
https://fedoraproject.org/wiki/Changes/SwapOnZRAM
Immediately: sudo systemctl stop swap-create@zram0
Permanently: sudo touch /etc/systemd/zram-generator.conf or sudo dnf remove zram-generator-defaults
Asking the interesting question: Why would you want to ever do this? RAM is ~10x faster than SSD and 100x faster than spinning disk. Unless your system is so ancient and CPU-constrained that you are unable to afford the relatively low compression costs, making use of all available RAM at all times seems like a better move than stopping ZRAM swap.
For what it is worth....
Prior to my memory upgrade, when I had only 8GB memory and Firefox just growing, I was seeing the following:
$ free total used free shared buff/cache available Mem: 7380668 6930852 262676 1492 187140 221144 Swap: 24157176 12044096 12113080
I did not know then about zram being the default, so I don't know how much of that 12GB swap was zram and how much was SSD.
But I can tell you that my system regularly 'hesitated' when I switched tasks. I had real wait time before I could do something. And at times I would be typing and the system did not respond. I had to wait a couple seconds before the screen was updated with whatever I was typing. Now this is on a Lenovo x140e with an SSD drive, using Xfce; granted an older platform but quad-core. Since the memory upgrade, there has been none of this hesitation. And I am right now seeing:
free total used free shared buff/cache available Mem: 15625916 10489292 598484 183664 4538140 4617552 Swap: 25165816 512 25165304
zramctl NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT /dev/zram0 lzo-rle 8G 496K 122.1K 380K 4 [SWAP]
this is after being running only 21hr. We will see how the system is doing in a few days, but swap was killing me. Was it real SSD r/w or zram compression?