this post was submitted on 06 Nov 2023
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I've never had a problem with ext4 after power failure.
Zram is not a substitute for swap. Your system is less optimal by not having at least a small swap.
Firewalls should never default to on. It's an advanced tool and it should be left to advanced users.
Not to mention how much grief it would cause distro maintainers. If they don't auto configure the firewall they get blasted by people who don't know why their stuff isn't working. If they auto configure they get blasted by people upset that the auto configurator dared change their precious firewall rules. You just can't win.
Honnestly. Firewalls shut be enabled by default. Specially on laptops connecting to public places.
A good default shut be choosen by the disteo maintainer. A default shut not overwrite your own config. Like any config really. So no upset folks that like to change the firewall. Also if you dont block much outgoing trafic you are not likely to run into problems. And for people that like to poke holes in the incoming trafic. Your a "advanced" user anyway.
So what should happen when the user installs a service that needs an open port in order to work? Presumably the whole point of installing it being to, you know, use it.
Their are not many programs that require open ports for incoming trafic. Things like ssh or a web server do. But then again those are services you would manualy want to open anyway.
What is the difference between physical swap and having a swap partition on ZRAM, especially for the kernel? To the best of my knowledge, nearly no Linux distribution supports suspend to disk any more, any ZRAM swap looks for the kernel like ... swap. Thanks to the virtual file system. Further, I have high trust in the Fedora community, which decided to use ZRAM.
We can agree to disagree about the firewalls, especially for people who don't now why their stuff isn't working, it protects them and is much better than having unconfigured services with open ports on a laptop in a public network IMHO.
Why does not having swap make the system less optimal? Considering obviously it has more than enough ram available.
Swap holds memory pages which are not currently used. Putting them out of the way will optimize the main RAM for normal operations.
It's not a huge difference on a modern fast system with lots of actual RAM but it can be felt on older systems and/or less RAM.
So it's not not having swap that makes the system "less optimal" but not having enough RAM if I understand correctly?
They go hand in hand. Given enough RAM you can keep the swap in RAM rather than on disk to make it faster, but you still need swap.
I'm confused, so if there's no swap, what is the system doing given enough RAM? What's the impact?
Perhaps this can help: https://chrisdown.name/2018/01/02/in-defence-of-swap.html
I have a question about swap.
My current rig has 64 gb, and I opted to not create a swap partition. My logic being I have more than enough.
The question is does swap ever get used for non-overflow reasons? I would have expected 64 GB to be more than enough to keep most applications in memory. (including whatever the kernel wants to cache)
I believe so, though I went without swap for a while myself and never noticed any issues. When in doubt a 1gb swap partition can't hurt.
Start with a small swap file (100 MB) and see how much gets used, no need to waste 1 GB.
I also have 64 GB and yes, it gets used. For very low quantities, mind you, we're talking couple hundred KB at most, and only if you don't reboot for extended periods of time (including suspend time).
Creating a big swap is not needed, but if you add one that's a couple hundred MB you will see it gets used eventually.
You don't have to create a swap partition, you can create a swap file (with dd, mkswap, swapon and /etc/fstab). You can also look into zswap.
Swap is not meant as overflow "disk RAM", it's meant as a particular type of data cache. It can be used when you run out of RAM but the system will be extremely slow when that happens and most users would just reboot.