Well again I'm all about "that depends on the workload", and environment and so on. Personally I'm not sure I would use ZFS og BtrFS on a laptop or any other FS that goes to great lengths to preserve my data perfectly, simply because the laptop has so many other reliability issues that external backup is the only solution that is good enough. So rather than paying the price for reliability all the time. I would run "unsafe" + backup on my laptop and get the performance advantage. At work i'd much rather use ZFS on BL460c G7 blades with HDS USP-V or AMS2xxx storage backends. They are not really slow even though there are disks inside.
"If you disagree [that Linux does not scale storagewise], try it yourself. Go mkfs a 500 TB ext-3/4 or other Linux file system, fill it up with multiple streams of data, add/remove files for a few months with, say, 20 GB/sec of bandwidth from a single large SMP server and crash the system and fsck it and tell me how long it takes. Does the I/O performance stay consistent during that few months of adding and removing files? Does the file system perform well with 1 million files in a single directory and 100 million files in the file system? My guess is the exercise would prove my point: Linux file systems have scaling issues that need to be addressed before 100 TB environments become commonplace. Addressing them now without rancor just might make Linux everything its proponents have hoped for."
Let me say you this. Regarding the current unstability of BTRFS and all bugs and so on, I doubt BTRFS does handle this situation. But you are convinced BTRFS does? I also doubt any other Linux filesystem handles this, because the senior consultant explains Linux can not handle this scenario with any filesystem. I doubt he lies. A liar never risk a situation where his lies could be revealed, a liar always says vague things. The consultant does not say vague things. He gives a clear and concrete example which have been done by many technicians. If the consultant lied about this concrete example, one of the technicians would have objected and it would have been spread on Linux sites that the senior consultant is a liar, and he would loose credibility and get bad reputation. A liar never gives concrete examples that are easy to double check. They always say vague things, that can never be double checked.
Sure, you have posted another link that tries to disprove the follow up article, but nothing concrete is said. There are mostly people saying stuff like "XFS is GREAT, it runs on LARGE installations, trust me!". It is only opinions, no hard facts. No scenarios. No examples. It could be FUD and lies. I am not saying that, but theoretically, it could be FUD and lies. Where are the links and benchmarks and white papers I ask of? Or any concrete examples that we can try out ourself? Of course, that senior consultant just assures us that Linux does not handle large filesystems without giving benchmarks, but he must speak true. This senior consultant gives us a concrete example to try out, and the risk is someone tries it out and the consultant has lied - then he will be crucified.
"So that's the ZFS ZIL in a nutshell. It's design was guided by previous years of frustration with UFS logging. We knew it had to be very fast as synchronous semantics are critical to database performance. We certainly learnt from previous mistakes."
How the heck do you expect that single BTRFS guy to know what is important? Is he all knowing? He knows as much as the whole Solaris developer team combined with the Enterprise Storage team? Is he best in the world? Or is he just an ordinary developer with high goals, though "BTRFS is broken by design" as a RedHat developer wrote?
Again. To do data integrity correctly, is VERY difficult. It requires VAST knowledge (see below). It is almost to try to make a software bug free - that requires vast experience of building systems, to know which common pitfalls there are, etc. I would not be surprised if BTRFS is the first or second filesystem he ever developed. That is hilarious: "BTRFS is a ZFS killer" developed by a guy who knows nothing about common pitfalls? I trust more an experienced team that has vast experience, than a single guy that have never set his foot into a large server hall.It seems that BTRFS is more tailored to desktops, than Enterprise halls. Dont you agree?
When you talk about Moore's law
"Moore's law is about transistor density on silicon. It has nothing to do with disk space."
Let us read more on this law, regarding hard drives part:
It turns out that hard drives have the same development, called Kryder's law:
"A similar law [as Moore's law] (sometimes called Kryder's Law) has held for hard disk storage cost per unit of information"
And there is a article in "Scientific American" about Kryder's law:
Which says that "says that magnetic disk areal storage density doubles annually"
Do you know enough math to understand what this means? It means EXPONENTIAL GROWTH, the same as Moore's law. And if you dont know theory about asymptotics, let me tell you. Exponential growth is a very bad thing, it grows extremely fast. It actually, grows exponentially. Therefore you are wrong on this. Your premise is false, and your entire reasoning is FAIL. And you say I dont understand arithmetic and math? Jesus. What are those Linux guys out there? Uneducated all of them? I cant help but wonder. Why am I wasting time pointing out errors in their juvenile reasonings?
Look, if anyone can prove me wrong, then I stop post that very thing. Until then, it is YOU that are wrong because I have evidence I am correct (research papers, articles, white papers, benchmarks, etc) and you have nothing. So I am correct. I dont make up things, nor FUD, etc. I can always link to white papers, research papers, scientif journals, etc. You Linux guys, can not. And you call me a FUDer and Troll? Jesus.If you prove me wrong with articles, I stop. If you prove me wrong, by yelling I am dumb and Troll - I continue. It is as simple as that. As long as I am right, and you are wrong, I continue. Prove me wrong. Use research papers, articles etc.
Let me cite you: "You, Kebabbert, are apparently one of the folks I was referring to who does not understand exponential growth". Great. It takes an igorant person to fail to see how fast hard discs have growed in size.
Jesus, give me strength. Why do I must correct all Linux people's misunderstandings all the time? Why do they think "ZFS and DTrace are slightly more polished than Linux counter parts"?
Look. Raid5 & 6 sucks big time. Your data is not safe with those. Here are some articles. Read them and please stop say things that are not true.
"Detecting and recovering from data corruption requires protection techniques beyond those provided by the disk drive. In fact, basic protection schemes such as RAID  may also be unable to detect these problems.
As we discuss later, checksums do not protect against all forms of corruption"
From above, you can not just add some checksums all over the place into BTRFS and expect to get data integrity. Ok? Not even mature techniques as Raid are safe (which many falsely believe). Do you finally understand now why I doubt BTRFS to be safe? Why must I educate all these Linux people all the time? *sigh*
"Recent work has shown that even with sophisticated RAID protection strategies, the “right” combination of a single fault and certain repair activities (e.g., a parity scrub) can still lead to data loss ."
I can add that CERN did a test on their Linux hardware raid, and data was corrupted. (CERN now migrates to ZFS machines)
A whole site with lots of articles dedicated to explain all the flaws in raid-5
"The paper explains that the best RAID-6 can do is use probabilistic methods to distinguish between single and dual-disk corruption, eg. "there are 95% chances it is single-disk corruption so I am going to fix it assuming that, but there are 5% chances I am going to actually corrupt more data, I just can't tell". I wouldn't want to rely on a RAID controller that takes gambles :-)"
Let me tell you, I have PLENTY of material on Silent corruption. Including many research papers. Just tell me if you want more information on silent corruption. Actually, it is very interesting read, to see how bad the situation is with current storage situation. (Please, someone ask me, to post all this material! )
ZFS is for Enterprise, that is, not a single disc, but zfs raid. If you have 48 ordinary SATA discs in your PC chassi without any raid controller card, you reach 2-3GB/sec read speed. That is plenty. If you also add SSD discs, your latency drops extremely much, in some cases, to a few millionths of a second. Your IOPS go far over 100.000. If you have 7 discs in a ZFS raid (without controller card) you can reach 430MB/sec in an ordinary PC. Do you call this "slow"? I would not. Do you want some links that proves everything I claim, or do you trust me on this? Of course I can link to every number I gave. It would be dumb of me to make up numbers and not be able to give links - no liar gives hard concrete numbers which are easy to prove or disprove.
Still, the MAIN POINT with ZFS is data integrity. Which no other common filesystem offers. Of course ZFS offers more perfomance than BTRFS, why would it not? We are talking about ZFS! The besto.
Is your data important to you? CERN says ZFS is the only filesystem that offers data integrity, even when considering very expensive enterprise storage systems. They are migrating away from Linux to ZFS. Is it because CERN is fooled by the ZFS hype and Sun marketing people, or is it because ZFS is actually best? For real?
I have read in a blog comment somewhere (not a good source, so we should not trust this information too much) that BTRFS is also a "layering violation". Does anyone know more on this?
And besides, I dont understand the fuss about layering violation. If ZFS is best on the market, it is. I do not care if it is written in pascal, has layering violation, is painted blue or whatever as long as it is best and protects your data. Would you prefer to use an inferior filesystem that does not protect your data, but has four layers instead of three layers?
Bonwick, the archictect behind ZFS explains that ZFS only has fewer layers (ZFS scrapped unnecessary layers that legacy filesystems have) but ZFS is still layered.
Show me a BTRFS machine that beats this ZFS machine (look at the right column)
Regarding the rest of your post, if Linux is faster than FreeBSD on desktop things, so what? FreeBSD is a Unix. As Solaris. They win by a large margin in the Enterprise halls. They are stable. Safe. Not unstable as Linux. Do you want to see links where Linux companies increase their work load much, and must switch to for instance, Solaris? Of course I have such links. I may be true that Linux is faster on desktop things - but is Linux good on Enterpirse with lots of CPUs? No? Linux looses on SAP benchmarks with many cores? Ah. Linux is not stable says many admins? Ah. Linux does not protect your data? Ah. BUT LINUX IS FASTER ON FPS! Wow.
Why are Linux people so ignorant and dont know how things REALLY are? It IS very tricky do data integrity, after many years, even raid does not succeed! Not even the old mature filesystems as "superior" XFS does not offer data integrity? And Linux people thinks that one guy will make BTRFS safe? Hilarious.
Whereas UFS which more similar to ext3, is many times bigger. Read the link. The point is, ZFS has ditched layers, so the code is minimal, compared to old bloated antique filesystems with unnecessary layers.
And you also claim the code was bad. Can you tell me more on this? Which code? Was it important code, or was it an unimportant shell script?
Yes I read the OpenSolaris forums, and I see that people have trouble with ZFS. I have never denied that. I had said earlier here, several times, that ZFS has bugs. But I also think ZFS is still the best out there. And it is rapidly maturing, thanks to the great Solaris developers.Do you read the forums? Do you SEE the problems that people are having with ZFS?
The opensolaris forum is one single forum. Every ZFS user goes there to post about ZFS, or complain. Meanwhile, the ext3 and other Linux filesystems are spread out on several different forums. I have read stories about Linux people loosing data too.
I dont doubt the Sun sales personal sucked. But I talk about the Sun engineers, that provenly does great and innovative tech that no one has thought of earlier. Tech that many OSes want. Solaris has not only ZFS and DTrace that is great, there are other great tech there, too.Ok.. so we have different opinions about Sun's expertise (expertise that bankrupt the company btw). That's ok... but I just want to make sure that people understand, there is ANOTHER side to the story apart from the slick marketing and persuasive arguments that Sun and its engineers tell.
Meanwhile, I dont see anything that makes devs drool about anything that Linux has. Sure, Linux gives better FPS in gaming, or graphics. But no one has denied Linux is a better desktop OS. But Enterprise use in another thing.
I wouldn't draw the conclusion that BtrFS is slower than ZFS, just because ZFS is so scalable. The similarities between BtrFS and ZFS are significant and one could say that BtrFS is an extension of ZFS. It might turn out faster and more scalable in the end, but currently it is too nice to call it beta stage IMHO. The basic problem with BtrFS is the data structure that has proven difficult to implement efficiently and might prove impossible to implement efficiently with all desirable features.
It is only a matter of ZFS configuration. Just add some more discs or SSD and you get more performance. ZFS handles the extra hardware automatically for you.
So, I just want to say this: "Muhahahaha" in your face. I TOLD you that ZFS is the best out there. ZFS does everything that other filesystems do, but better. But on top of that, ZFS gives DATA INTEGRITY. That is the ONLY reason to run ZFS. Sure, ZFS is extremely fast in Enterprise settings but that is not the reason to use ZFS. It is data safety.
BTW, Phoronix doesnt do Enterprise benchmarks. If Phoronix did, Linux would loose on every benchmark. Solaris is since long, targeted to Enterprise. Not Desktop. Phoronix only do Desktop benchmarks: single computer, 8 cores benchmarks, single disc, etc. That is chicken shit. When we talk about large Enterprise stuff, then Linux just doesnt cut it. Linux is a great DesktopOS. I admit it. Linux is better DesktopOS than OpenSolaris or Solaris.
But, desktop and Enterprise are different things. People here, just don't understand it. They see BTRFS is faster on single disc (a desktop benchmark), and draw the conclusion "BTRFS is ZFS killer". Jesus. How can you compare Desktop vs Enterprise, that easy???
If we ventured into the realms of LARGE servers giving huge performance, people would understand the true strength of Solaris, ZFS, DTrace and all other Solaris tech. They just dont have any experience of it, so they believe it is just to add some cpus, discs, etc to Linux and then you have Enterprise. No, up comes lots of different, new scalability problems that are very hard to solve. IBM AIX which is very mature and high end, didnt scale well cpu wise, until recently. It IS difficult to scale well. Enterprise IS difficult.
So, where was OpenSolaris in all this? Seeing as it's the native environment to run ZFS in?