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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.

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What's with all these hip filesystems and how are they different? (lm.paradisus.day)

submitted 11 months ago* (last edited 11 months ago) by [email protected] to c/[email protected]

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You know, ZFS, ButterFS (btrfs...its actually "better" right?), and I'm sure more.

I think I have ext4 on my home computer I installed ubuntu on 5 years ago. How does the choice of file system play a role? Is that old hat now? Surely something like ext4 has its place.

I see a lot of talk around filesystems but Ive never found a great resource that distiguishes them at a level that assumes I dont know much. Can anyone give some insight on how file systems work and why these new filesystems, that appear to be highlights and selling points in most distros, are better than older ones?

Edit: and since we are talking about filesystems, it might be nice to describe or mention how concepts like RAID or LUKS are related.

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[–] [email protected] 14 points 11 months ago (2 children)

ZFS cache will mark itself as such, so if the kernel needs more RAM for applications it can just dump some of the ZFS cache and use whatever it needs.

I see lots of threads on homelab where new users are like “HELP MY ZFS IS USING 100% MEMORY” and we have to talk them off that ledge: unused RAM is wasted RAM, ZFS is making sure you’re running fast AF.

[–] [email protected] 7 points 11 months ago

ZFS cache will mark itself as such, so if the kernel needs more RAM for applications it can just dump some of the ZFS cache and use whatever it needs.

In theory. Practically unless I limit the max ARC size, processes get OOM killed quite frequently here.

[–] [email protected] 4 points 11 months ago* (last edited 11 months ago) (1 children)

unused RAM is wasted RAM

In theory. But how it is implemented in current systems, reserved memory can not be used by other processes and those other processes can not just ask the hog to give some space. Eventually, the hog gets OOM-killed or the system freezes.

[–] [email protected] 1 points 11 months ago

Even when, as the comment says, the memory is marked as cache?

Windows doesn't have this problem