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Bcachefs Goes to "Externally Maintained"

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Re: Bcachefs Goes to "Externally Maintained"

#341

Post by trueismywork »

koverstreet wrote: post #338
trueismywork wrote: post #314

Earlier quoted context omitted.

You're arguing in circles. Either bcachefs is experimental and hence needs a lot of changes and tools to make sure that users dont lose data and hence the fixes are not critical/users can use a custom branch. Or it is stable and the only thing users need is actual big fixes. Not new tools in an RC3. Don't compare bcachefs with btrfs for stability. Compare it with ext4. (And dont care anecdotal data, compare the proce…

So, are we agreeing that btrfs isn't fit for purpose, then?

I don't understand your question. Are you going somewhere with this?

Re: Bcachefs Goes to "Externally Maintained"

#342

Post by immibis »

koverstreet wrote: post #328
immibis wrote: post #327

Earlier quoted context omitted.

You're still doing that thing where you assume everyone else is you. Linus's job (some of which he delegates) is to take the contributions from ALL the hundreds of maintainers, and bundle it into a unified coherent whole. He is not only responsible for bcachefs reliability. In the train analogy I already used, he is the train driver, he is responsible for getting everyone who is on the train to their destination, but…

We're not talking about situations where the bcachefs changes could plausibly affect the rest of the kernel, and I am well known even within the kernel community for being on top of potential issues and responsive on bugs.

The merge window policy is not limited to cases where the new bcachefs features affect the rest of the kernel.

Re: Bcachefs Goes to "Externally Maintained"

#343

Post by tomhow »

quotemstr wrote: post #316
ranger_danger wrote: post #313

Earlier quoted context omitted.

Claims made without evidence can be dismissed without evidence.

[flagged]

> Building an argument without citing a source is called "thinking for yourself". You should try it.

You've been on HN well and truly long enough to know this is not an acceptable way to comment here.

Re: Bcachefs Goes to "Externally Maintained"

#344

Post by cyphar »

aaronmdjones wrote: post #252
evanjrowley wrote: post #129

Earlier quoted context omitted.

Sometimes I wonder how someone so talented could be so wrong about ZFS, and it makes me wonder if his negative responses to ZFS discussions could be a way of creating plausible deniability in case Oracle's lawyers ever learn how to spell ZFS.

As far as I know, the license incompatibility is on the GPL side of the equation. As in, shipping a kernel with the ZoL functionality is a violation of the GPL, not the CDDL. Thus, Oracle would not be able to sue Canonical (Edit: or, rather, have any reasonable expectation of winning this battle), as they have no standing. A copyright holder of some materially significant portion of the GPL code of the kernel would h…

The Software Freedom Conservancy did a legal analysis and concluded that the incompatibility comes from both sides[1]. This also applies to the pre-2.0 MPL that CDDL was based on.

A lot of people focus on the fact that the CDDL allows binaries to be arbitrarily licensed so long as you provide the sources, but the issue is that the GPL requires that the source code of both combined and derived works be under the GPL and the CDDL requires that the source code be under the CDDL (i.e., the source code cannot be sublicensed). This means that (if you concluded that OpenZFS is a derived work of Linux or that it is a combined work when shipped as a kernel module) a combination may be a violation of both licenses.

However, the real question is whether a judge would look at two open source licenses that are incompatible due to a technicality and would conclude that Oracle is suffering actual harm (even though OpenZFS has decades of modifications from the Oracle version). They might also consider that Oracle themselves released DTrace (also under the CDDL) for their Linux distribution in 2012 as proof that Oracle doesn't consider it to be license violation either. If we did see Canonical get sued, maybe we'd finally be able to find out through discovery if the CDDL was intentionally designed to be GPL incompatible or not (a very contentious topic).

[1]: https://sfconservancy.org/blog/2016/feb/25/zfs-and-linux/

Re: Bcachefs Goes to "Externally Maintained"

#345

Post by cyphar »

p_l wrote: post #322
messe wrote: post #312

Earlier quoted context omitted.

I think you might have missed the point. Yes. Oracle have that copyright. That's the whole fucking point. Anything from before the fork is still licensed (and pretty much everything after) is still under the CDDL which is possibly in conflict with the GPL.

Oracle can't do anything. They can't relicense code that was already released as CDDL in any form other than what they did when they closed down Solaris. The CDDL being unacceptable is the same issue that GPL3 or Apache is unacceptable - unlike GPLv2, CDDL mandates patent licensing as far as the code is considered.

Oracle is the license steward for CDDL, they have the right to release CDDL-2.0 and make it GPL-compatible which users would then be allowed to chose to use. Mozilla did the same thing with MPL-2.0 (CDDL was based on MPL-1.0), though the details are a little more complicated.

Unlike the GPL, the CDDL (and MPL) has an opt-out upgrade clause and all of OpenSolaris (or more accurately, almosf all software under the CDDL) can be upgraded to "CDDL-1.1 OR CDDL-2.0" unilaterally by Oracle even if they do not own the copyrights. See section 4 of the CDDL.

Re: Bcachefs Goes to "Externally Maintained"

#346

Post by wtallis »

m-p-3 wrote: post #301
dmm wrote: post #66

Earlier quoted context omitted.

btrfs is fine for single disks or mirrors. In my experience, the main advantages of zfs over btrfs is that ZFS has production ready raid5/6 like parity modes and has much better performance for small sync writes, which are common for databases and hosting VM images.

Context: I mostly dealt with RAID1 in a home NAS setup A ZFS pool will remain available even in degraded mode, and correct me if I'm wrong but with BTRFS you mount the array through one of the volume that is part of the array and not the array itself.. so if that specific mounted volume happens to go down, the array becomes unavailable unmounted until you remount another available volume that is part of the array whi…

> with BTRFS you mount the array through one of the volume that is part of the array and not the array itself

I don't think btrfs has a concept of having only some subvolumes usable. Either you can mount the filesystem or you can't. What may have confused you is that you can mount a btrfs filesystem by referring to any individual block device that it uses, and the kernel will track down the others. But if the one device you have listed in /etc/fstab goes missing, you won't be able to mount the filesystem without fixing that issue. You can prevent the issue in the first place by identifying the filesystem by UUID instead of by an individual block device.

Re: Bcachefs Goes to "Externally Maintained"

#347

Post by wtallis »

guenthert wrote: post #188
ThatPlayer wrote: post #83

Earlier quoted context omitted.

For me bcachefs provides a feature no other filesystem on Linux has: automated tiered storage. I've wanted this ever since I got an SSD more than 10 years ago, but filesystems move slow. A block level cache like bcache (not fs) and dm-cache handles it less ideally, and doesn't leave the SSD space as usable space. As a home user, 2TB of SSDs is 2TB of space I'd rather have. ZFS's ZIL is similar, not leaving it as usab…

> automated tiered storage. I've wanted this ever since I got an SSD more than 10 years ago, but filesystems move slow. You were not alone. However, things changed, namely SSD continued to become cheaper and grew in capacity. I'd think most active data is these days on SSDs (certainly in most desktops, most servers which aren't explicit file or DB servers and all mobile and embedded devices), the role of spinning rus…

Tiering didn't go away with the migration to all-SSD storage. It just got somewhat hidden. All consumer SSDs are doing tiered storage within the drive, using drive-specific heuristics that are completely undocumented, and host software rarely if ever makes use of features that exist to provide hints to the SSD to allow its tiering/caching to be more intelligent. In the server space, most SSDs aren't doing this kind of caching, but it's definitely not unheard-of.

Re: Bcachefs Goes to "Externally Maintained"

#348

Post by wtallis »

Filligree wrote: post #242
wtallis wrote: post #61

Earlier quoted context omitted.

BTRFS does have stable, usable multi-disk support. The RAID 0, 1, and 10 modes are fine. I've been using BTRFS RAID1 for over a decade and across numerous disk failures. It's by far the best solution for building a durable array on my home server stuffed full of a random assortment of disks—ZFS will never have the flexibility to be useful with mismatched capacities like this. It's only the parity RAID modes that BTRF…

That’s nice and all, but I have five disks in my server. I want the 6 mode. In practice RAIDZ2 works great.

In the case of five disks of the same capacity, RAID6 or RAIDZ2 only gets you 20% more capacity than btrfs RAID1. That's not exactly a huge disparity, usually not enough to be a show-stopper on its own. There are plenty of scenarios where the features ZFS has which btrfs lacks are more important than the features that btrfs has which ZFS lacks. My point is simply that btrfs RAID1 has its uses and shouldn't be dismissed out of hand.

Re: Bcachefs Goes to "Externally Maintained"

#349

Post by AaronFriel »

goneri wrote: post #145
qalmakka wrote: post #141

The whole situation is moronic at best. Linux needs a decent modern filesystem in tree. ZFS would easily be it, but unfortunately Sun decided back in the '00s to fuck Linux because they wanted to push Solaris instead. Little they knew ZFS ended up being FreeBSD top feature for years. Btrfs is constantly eating people data, it's a bad joke nowadays. Right now on Linux you're basically forced to constantly deal with ou…

Btrfs is NOT constantly eating people data. You have nothing to back this statement. It's widely used and the default filesystem of several distributions. Most of the problems are like for the other filesystem: caused by the hardware. I've been using it for more than 10 years without any problem and enjoy the experience. And like for any filesystem, I backup my data frequently (with btrbk, thanks for asking).

I think any discussion of btrfs needs to acknowledge that raid5/6 support was promised in the early years, shipped in the kernel in 2013 and, until 2021's btrfs-progs 5.11 release, did not warn users that they risked data loss when creating volumes.

For near a decade btrfs raid5/6 was "unsafe at any speed" and many people lost data to it, including myself.

Re: Bcachefs Goes to "Externally Maintained"

#350

Post by xelxebar »

ofrzeta wrote: post #28
betaby wrote: post #12

The sad part, that despite the years of the development BTRS never reached the parity with ZFS. And yesterday's news "Josef Bacik who is a long-time Btrfs developer and active co-maintainer alongside David Sterba is leaving Meta. Additionally, he's also stepping back from Linux kernel development as his primary job." see https://www.phoronix.com/news/Josef-Bacik-Leaves-Meta There is no 'modern' ZFS-like fs in Linux n…

Suse Linux Enterprise still uses Btrfs as the Root-FS, so it can't be that bad, right? What is Chris Mason actually doing these days? I did some googling and only found out that he was working on a tool called "rsched".

I've used btrfs for 5-ish years in the most mundane, default setup possible. However, in that time, I've had three instances of corruption across three different drives, all resulting in complete loss of the filesystem. Two of these were simply due to hard power failures, and another due to a flaky cpu.

AFAIU, btrfs effectively absolves itself of responsibility in these cases, claiming the issue is buggy drive firmware.

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