I dont understand your excitement of me confirming that ZFS does not cluster? Everybody knows it, Sun explained ZFS does not cluster, Oracle confirms it, and everybody says so, including me. You know that I always try to back up my claims with credible links to research papers / benchmarks / etc, and there are no links that say ZFS does cluster - because it does not. Therefore I can not claim that ZFS does cluster.
Are you trying to imply that I can not admit that ZFS is not perfect, that is has flaws? Why? I never had any problems looking at benchmarks superior to Sun/Oracle and confirming that, for instance, that POWER7 is the fastest cpu today on some benches. I have written it repeatedly, POWER7 is a very good cpu, one of the best. You know that I have said so, several times. I have confirmed superior IBM benchmarks, without any problems.
Of course ZFS has its flaws, it is not perfect, nor 100% bullet proof. It has its bugs, all complex software has bugs. You can still corrupt data with ZFS, in some weird circumstances. But the thing is, ZFS is built for safety and data integrity. Everything else is secondary. ZFS does checksum calculations on everything, that drags down performance, which means performance is secondary to data integrity. Linux filesystems tend to sacrifice safety to performance. As ext4 creator Ted Tso explained, Linux hackers sacrifice safety to performance:
"In the case of reiserfs, Chris Mason submitted a patch 4 years ago to turn on barriers by default, but Hans Reiser vetoed it. Apparently, to Hans, winning the benchmark demolition derby was more important than his user's data. (It's a sad fact that sometimes the desire to win benchmark competition will cause developers to cheat, sometimes at the expense of their users.)...We tried to get the default changed in ext3, but it was overruled by Andrew Morton, on the grounds that it would represent a big performance loss, and he didn't think the corruption happened all that often (!!!!!) --- despite the fact that Chris Mason had developed a python program that would reliably corrupt an ext3 file system if you ran it and then pulled the power plug "
I rely on research and official benchmarks and other credible links when I say something. Scholars and researchers do so. You, OTOH, do not. I have showed you several research papers - and you reject them all. To me, an academic, that is a very strange mindset. How can you reject all the research on the subject? If you do, then you can as well as rely on religion and other non verifiable arbitrary stuff, such as Healing, Homeopathy, etc. That is a truly weird charlatan mindset: "No, I believe that data corruption does not occur in big data, I choose to believe so. And I reject all research on the matter". Come on, are you serious? Do you really reject research and rely on religion instead? I am really curious. O_o
So yes, ZFS does not cluster. If you google a bit, you will find old ZFS posts where I explain that one of the drawbacks of ZFS is that it doesnt cluster. It is no secret. I have never seen you admit that Sun/Oracle has some superior tech, or seen you admit that HP tech has flaws? On my last job, people said that HP OpenVMS was superior to Solaris, and some Unix sysadmins said that HP Unix was the most stable Unix, more stable than Solaris. I have no problems on citing others when HP/IBM/etc is better than Sun/Oracle. Have you ever admitted that Sun/Oracle did something better than HP? No? Why are you trying to make it look like I can not admit that ZFS has its flaws? Really strange....
"...If I stick FreeNAS on an old desktop and hawk it on eBay am I "competing with EMC"?..." No, I dont understand this. What are you trying to say? That Nexenta is on par with FreeNAS DIY stuff? In that case, it is understandable that you believe so. But if you study the matter a bit, Nexenta beats EMC and NetApp in many cases, and Nexenta has grown triple digit since its start. It is the fastest growing startup. Ever.
Thus, FreeNAS PC can not compete with EMC, but Nexenta can. And does. Just read the articles or will you reject the facts, again?
"...Both hp and IBM are a good case in point. Both pay license fees to Symantec to use their proprietary LVM for their filesystems. If ZFS was so goshdarnwonderful as you say, and "free" to boot, surely hp or IBM would be falling over themselves to use ZFS? They aren't. ..."
Well, DTrace is another Solaris tech that is also good. IBM has not licensed DTrace, nor has HP. What does that prove? That DTrace sucks? No. Thus, your conclusion is wrong: "If HP and IBM does not license ZFS it must mean that ZFS is not good" - is wrong because HP and IBM has not licensed DTrace.
IBM AIX has cloned DTrace and calls it Probevue
Linus has cloned DTrace and calls it Systemtap
FreeBSD has ported DTrace
Mac OS X has ported DTrace
QNX has ported DTrace
VMware has cloned DTrace and calls it vProbes (gives credit to DTrace)
NetApp has talked about porting DTrace on several blogs
Look at this list. Nor HP nor IBM has licensed DTrace, does that mean DTrace sucks? No. Wrong conclusion of you. DTrace is the best tool to instrument the system, and everybody wants it. It is best. Same with ZFS.
"...There is a reason - ZFS is not as good as you think and there are other options, especially on Linux, that are far superior..." Fine, care to tell us more about those options that are far superior to ZFS? What would that be? BTRFS, that does not even allow raid-6 yet? Or was it raid-5? Have you read the mail lists on BTRFS? Horrible stories of data corruption all the time. Some Linux hackers even called it "broken by design". Havent you read this link? Want to see? Just ask me, and I will post it.
So, care to tell us the many superior Linux ZFS options? A storage expert explains that Linux does not scale I/O wise, and you need to use real Unix: "My advice is that Linux file systems are probably okay in the tens of terabytes, but don't try to do hundreds of terabytes or more."
"...There is a demonstratable case for ECC RAM. There is not for ZFS, despite what you claim...."
Fine, but have you ever noticed ECC firing? Have you ever seen it happen? No? Have you ever seen SILENT corruption? Hint, it is not detectable. Have you seen it?
Have you read experts on big data? I posted several links, from NetApp, Amazon, CERN, researchers, etc. Do you reject all those links that confirm that data corruption is a big problem if you go up in scale? Of course, when you toy with your 12TB hardware raid setups, you will never notice it. Especially as hw-raid is not designed to catch data corruption. Nor SMART does help. Just read the research papers. Or do you reject Amazon, CERN and NetApp and all researchers? What is it you know, that they dont know? Why dont you tell NetApp that their big study on 1.5 million Harddisks did not see any data corruption at all? They just imagined the data corruption?
"A real life study of 1.5 million HDDs in the NetApp database found that on average 1 in 90 SATA drives will have silent corruption which is not caught by hardware RAID verification process; for a RAID-5 system that works out to one undetected error for every 67 TB of data read"
Are you serious when you reject all this evidence from NetApp, CERN and Amazon, or are you just Trolling?