Why btrfs rather than zfs?

[RLynwood]

Hello, all. Since Kubuntu is Ubuntu (using KDE/Plasma), and Ubuntu is transitioning to zfs, why would the Kubuntu community be interested in the admittedly great btrfs? I understand--without having learned anything about either--than zfs is at least as great as btrfs if not better. So, as I said above, given that Ubuntu is transitioning to zfs & Kubuntu IS Ubuntu, why isn't the community making commensurate preparations? I really want to know about this. Thanks.

[jlittle]

My 2c

• ZFS has an even longer and steeper learning curve than btrfs; my perspective is that of someone who has failed to ascend it.
• ZFS is owned by Oracle, who are untrustworthy. Yes, I know about OpenZFS, but Oracle has screwed over similar efforts in the past. cf Linus Torvald's statements about it.
• The system resources recommended for ZFS seem far too high. Running 5-10 installs on the same small SSD as I sometimes do would be difficult.
• ZFS was developed to get speed and reliability from multiple spinning discs; not a good fit for today's hardware on the desktop.

[RLynwood]

JLittle, your comments seem apt for an individual's concerns, but they completely miss my point. Ubuntu is working on including zfs now for a soon future version of Ubuntu, perhaps as soon as 22.04. To repeat, since Kubuntu IS Ubuntu with KDE's Plasma DE, I want to know how vigorously the Kubuntu devs are working on seeing to it that Plasma works smoothly with it? Or are they working on this at all? Is this part of their dev. plans?

[jlittle]

...]given that Ubuntu is transitioning to zfs

I'm not sure what you mean by that. Ubuntu is making, or has made, ZFS an option for Ubuntu installs. Previously one would have to add ZFS separately, kind of tricky for a new install.

I don't expect ZFS to be the default for desktop installs. I imagine some think making btrfs the default, as Fedora and OpenSUSE have done, is a step too far. I think Kubuntu will continue to support lots of file systems in its installer, including ext4 and btrfs.

I want to know how vigorously the Kubuntu devs are working on seeing to it that Plasma works smoothly with it?

I'd have thought that desktop environments, such as Plasma, are mostly agnostic about the underlying file system type. Every video I've seen about, or referring to, ZFS, has shown commands being run in a shell. What desktop environment integration would you like to see?

[GreyGeek]

I would second jlittle's comments.

Kubuntu dev's aren't concerned with the undelying root file system. It doesn't matter to them what you use: FAT32, EXT2, EXT4, BTRFS, ZFS, ReiserFS, etc... Why should it? Most, if not all, DE's isolates themselves from the hardware by using calls to the glibc and libc6 layers. KDE's Qt API is modular, polymorphic and full featured. World class. Qt 4.0 API was the last dev API I used before I retired from programming in 2008.

BTRFS is autotuning. There are VERY FEW adjustments that the user can make. Switch a subvolume from r to rw or visa-versa is the only practical one I can think of at the moment. ZFS, on the other hand, has DOZENS of tuning parameters. If you are a db or system admin and need to fine-tune the root file system to maximize your throughput then have at it. BTRFS can run in 4GB of regular RAM. I have 16GB of RAM and BTRFS has been faultless for me since 2016. ZFS works best running in 32GB or more of ECC RAM, but some claim it runs OK in 8GB of regular RAM. ECC RAM used to be very expensive but now you can get 32GB from Amazon for $175.

Most of the videos about setting up ZFS on Ubuntu are focusing on Ubuntu servers, not user desktops.
https://www.youtube.com/results?sear...IIBQ%253D%253D

Snapshots in BTRFS and in ZFS are totally different animals. When I make a BTRFS snapshot of @ (root, or /), say @202110101421, it stands as an independent subvolume. Another snapshot of @, @202110101430, made 9 seconds later, is independent of the 1421 snapshot. IF I delete the 1421 snapshot the 1430 snapshot remains and can be used to recover my system. Say I was running ZFS and created a third snapshot, @202110101452. If I decide to delete the 1430 snapshot. That will result in deleting the 1452 snapshot, leaving me only with the 1421 snapshot. Now, I understand that there are ways to overcome this using clone, or other commands, but when I encountered this problem during my testing of ZFS I decided it wasn't a COW filesystem that I wanted or needed to run. Someone with more experience using ZFS than I have should chime in here and add to the conversation.

Even though Facebook uses BTRFS to power hundreds of thousands of its servers without significant problems, IMO BTRFS is the perfect file system for personal computers, SOHO and small businesses. Especially one drive PC's. With the latest version of TimeShift creating snapshots and rolling back to a previous one to recover from a problem becomes child's play. Yes, I know, I used to write ill of TimeShift, but that was about its previous configuation. The newer version uses the /mnt/@, /mnt/@home and /mnt/snapshots configuation to store snapshots, which is pretty close to what I use. My only complaint about TimeShift is that it doesn't emphasize snapshotting @home. I always used to create snapshots in pairs, @ and @home with the same extension, @yyyymmddhhmm. I got tired of doing the pair so I copied @home/jerry into /home/jerry and commented out the stanza in fstab that mounted @home to /home. Then I deleted @home and rebooted. Now, I have to snapshot only @, and it includes my home account. When I was snapshotting @ and @home I never mix a root snapshot with a differently timed home snapshot. In my /opt directory I have a google folder, a vivaldi folder and a wine-stable folder. Their configs are in my home account, /home/jerry/.config or ~/.wine, etc.... Recoving using @ from one time and @home from another time and you may end up with some broken apps.

Ubuntu adding the ability to install ZFS as the rootfs during the install is a good thing, because choice is a good thing. And, if they do as good a job with ZFS as they did with BTRFS then it will be a good option to choose, IF you can figure out the proper configuration for your use case. So, IMO, regardless if you choose BTRFS or ZFS you'll have a winner either way.

[oshunluvr]

I have no experience with ZFS mostly because all my reading indicates there is no reason to even try it. I have not read about one single actual benefit of using ZFS over BTRFS for an average desktop/laptop user. Most similar operations like compression and snapshots seem vastly more complex using ZFS.

Even this info: https://rudd-o.com/linux-and-free-so...0file%20system.

almost none of it applies to normal (non-enterprise) users and is written with such a slant that I am left feeling that the author is just another ZFS fanboi and has no actual practical experience attempting to use BTRFS.

[oshunluvr]

Oh yeah, I almost forgot:

Why ZFS over BTRFS?

[GreyGeek]

I like rudd-o-com. I just disagree with his statements about ZFS vs BTRFS. Most of his BTRFS claims appear to be more historic than current. He's pretty knowledgable on ZFS and if I were going to use ZFS I'd consult his experience while ignoring his BTRFS trash talk.
The article you cited is pretty far down on page 2 of his list of articles about Linux.

My guess is that he realizes that ZFS is not picking up support in the non-server market as rapidly as he thought it would, and he's attacking BTRFS because it IS rapidly gaining market share and replacing EXT4 as the default file system. If it were between ZFS, BTRFS or EXT4 and BTRFS stopped being supported I'd switch to EXT4 and use my old tar scripts to create my incremental tarfiles as a backup plan. I used them for years while running EXT4. That was back when we never turned off our computers and all service tasks were cron jobs.

A side note: He has an article that predicts the demise of personal computers within 15 years.
https://rudd-o.com/linux-and-free-so...uting-will-die

I'm here today to make a prediction.
General-purpose computing will all but become contraband activity.
Running Linux without permission on your own hardware will become a distant memory. Running "unpermitted" computer programs will become impossible. All of this will be accomplished incrementally.
This prediction is a rough sketch of how it will happen.

I turned 80 on 8/8/21. I don't expect to see this distopian future but my grandkids will. It saddens me because if that comes to pass, then it means the end of America and our freedoms and personal liberty as we've known them.