Shulou(Shulou.com)06/01 Report--

This article shows you an example analysis of Torvalds refusing to accept the ZFS file system, which is concise and easy to understand, which will definitely brighten your eyes. I hope you can get something through the detailed introduction of this article.

Linus Torvalds, the inventor and lead developer of Linux, recently publicly opposed the ZFS file system. The timing of this statement should not be ignored, as ZFS has only recently been officially implemented in a major release for the first time. This distribution is Ubuntu 19.10, in which the ZFS file system is hailed as one of the main features of the latest Linux version of Canonical.

"if someone adds a kernel module like ZFS, they maintain it themselves," Torvalds wrote in a forum post. "I won't maintain such a kernel module, and I can't be bound by other people's kernel changes."

If the reader only considers this post from Torvalds, it is easy to conclude that his objection to ZFS stems from potential licensing problems. "unless I get a formal Oracle letter signed by Oracle's principal legal adviser or preferably by Larry Ellison himself, saying that I can merge ZFS code and treat the final result as a license to comply with GPL, I cannot merge any ZFS code," he wrote.

The issue of licensing goes a little deeper. You know, ZFS on the Linux port relies on two deprecated kernel functions: _ _ kernel_fpu_begin () and _ _ kernel_fpu_end (). The functions that replace _ _ kernel_fpu_begin () and _ _ kernel_fpu_end () are intentionally released for GPL licenses only.

Therefore, if Oracle has not formally agreed to ZFS to adopt the GPL license, and the two deprecated functions that ZFS relies on are replaced by functions that are only for GPL licenses, there is a problem (even if it is only ideological at the moment).

But it's not just about GPL. The cause of this problem is a complaint that the Linux kernel has recently broken the out-of-tree ZFS module. Torvalds said: "Please note that'We don't destroy users'is really about user-space applications, about the kernel I maintain." Torvalds then boiled it down again to the licensing issue, saying, "but given the litigious nature of Oracle, coupled with licensing issues, I would never rest assured."

There are other problems with ZFS. The biggest problem is that it destroys the OSI 7-tier model. Specifically, ZFS uses its own error correction mechanism, thus avoiding trust in the lower layers of the Open Systems Interconnection (OSI) model. Keep in mind that the goal of the OSI 7-layer model is to interoperate various communication systems with standard communication protocols. As a result, your entire file system avoids the model that Linux depends on.

To make matters more complicated, ZFS provides the functionality that a few production-level Linux file systems have. The only comparable file system is Btrfs, which is often criticized for being unstable enough to be used in production systems.

Finally, Torvalds said, "Don't use ZFS. It's that simple. I think it's always more of a buzzword than any other system; for me, licensing issues make ZFS a filesystem completely unworthy of consideration." He further said: "in the benchmark tests I have seen, the results of ZFS are not very good. As far as I know, it is no longer really maintained, so from a long-term stability point of view, why do you use it?"

What does Canonical think of this? "judging from the recent discussions on ZFS, our customers and users have told us that they want ZFS in Ubuntu because ZFS has many of the features needed to prevent data corruption, support high storage capacity, provide efficient data compression, snapshots and replication-on-write cloning," Martin Wimpress, Canonical's engineering director, wrote in an email. We will continue to work with friends in the OpenZFS project to improve ZFS on Ubuntu. "

The reader just wants to know what happens next to the ZFS file system. Is it possible that Oracle will relicense the code so that it becomes "friendly" with the mainline kernel? If not, Torvalds is likely to continue to be indifferent to ZFS.

The above is an example of Torvalds refusing to accept the ZFS file system. Have you learned any knowledge or skills? If you want to learn more skills or enrich your knowledge reserve, you are welcome to follow the industry information channel.

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