Date: Mon, 22 Oct 2018 10:28:35 -0600 From: Alan Somers <asomers@freebsd.org> To: vijju.singh@gmail.com Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Subject: Re: SNIA SDC 2018 recap Message-ID: <CAOtMX2g3KRP8MYxbv42rf5=QC3aW3ehF0JxShBGnQ9QQsPvzsQ@mail.gmail.com> In-Reply-To: <CALCNsJRO%2BdkGY30KW-MM2oQ2p3nQjSet7C3hhFZaaQg7NV1b3Q@mail.gmail.com> References: <CAOtMX2hxuLqQFKsO8guaAgNb=3QEZ4VPEq_QW=F0KZF96qYy0g@mail.gmail.com> <CALCNsJRO%2BdkGY30KW-MM2oQ2p3nQjSet7C3hhFZaaQg7NV1b3Q@mail.gmail.com>
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Ahh, I didn't notice. Were you associated with your employer? -Alan On Mon, Oct 22, 2018 at 10:23 AM Vijay Singh <vijju.singh@gmail.com> wrote: > I was there as well Alan :) > > On Mon, Oct 22, 2018, 9:13 AM Alan Somers <asomers@freebsd.org> wrote: > >> The SNIA Storage Developers' Conference was held in Santa Clara during the >> last week of September. Jim Harris, John Hixon, Nick Principe, Michael >> Dexter, and myself attended. As far as FreeBSD goes, here's a summary of >> the juiciest bits: >> >> NVDIMM/PMEM: A lot of companies are still pushing persistent memory >> products. They're getting better, but still quite vendor-specific. >> Fortunately, there are standardization efforts in place. JEDEC is >> standardizing the hardware (NVDIMM-N, NVDIMM-P, NVDIMM-F). Every major >> memory company (but not CPU company) is on-board. SNIA is also trying to >> standardize a programming model (but not the precise API). Windows and >> Linux currently support it, with differences. There will probably be some >> additional changes to the model. >> https://static.ptbl.co/static/attachments/187585/1537988510.pdf?1537988510 >> . iX Systems reported some impressive benchmarks using an NVDIMM as a ZFS >> slog device. Several databases are adding pmem support. A few >> filesystems >> have some level of NVDIMM support, and the NOVA filesystem is being >> written >> from the ground up to take full advantage of NVDIMM. For example, >> directories are stored as in-memory data structures that never get >> serialized. The lesson here is that FreeBSD needs to support the standard >> NVDIMM programming model too. >> >> OpenChannel SSDs: These are SSDs that expose more of their internal >> implementation details to the host. Specifically, they rely on the host >> for at least part of garbage collection. They also expose their multiple >> internal busses to the host, so it can choose how to stripe data across >> them. Overall, the programming model is surprisingly similar to that of >> SMR hard drives. Unfortunately, the standard is a bit murky. Different >> speakers could not even agree on whether there is a standard. This is the >> best presentation on the topic: >> https://static.ptbl.co/static/attachments/187321/1537829929.pdf?1537829929 >> and this is the closest thing there is to a standard ATM: >> https://openchannelssd.readthedocs.io/en/latest/ . The lesson here is >> that >> FreeBSD needs to plumb these devices' properties up to userland and >> perhaps >> expose them in zonectl(8) (easy) and add filesystem support (very hard). >> >> NVMe: If there were an award for most popular buzzword, it would've gone >> to >> "NVMe". Everybody and their mother had something to say about it. But I >> personally paid little attention (except as regards OpenChannel). >> >> Seagate dual-actuator hard drives: Seagate is coming out with hard drives >> that pack two servos into a single case. Each servo can access half of >> the >> platters. The drive reports each servo as a separate LUN to the host. >> There is little FreeBSD needs to do here. To make zfsd(8) work correctly, >> we should add lun info to the drives' physical path strings. And it might >> be nice if zpool(8) prevented the user from adding both LUNs of the same >> physical drive to the same RAID group. But that's arguably out of our >> domain. >> >> SPDK: The storage-plane developer's kit is like Intel's version of Netmap, >> but for storage. It's a say for userland programs to access storage >> devices directly, bypassing the kernel. The benefits are negligible for >> spinning media, but can be significant for fast NVMe drives. SPDK has >> multiple backends for different I/O controllers, including some that are >> kernel-based. Notably lacking is a POSIX AIO backend. That's probably >> the >> biggest gap in its FreeBSD support. >> >> iX Systems wrote a blog post about the conference, too. It covers >> Swordfish and Samba, two topics I ignored. >> >> https://www.ixsystems.com/blog/snia-sdc-2018/ >> >> -Alan >> _______________________________________________ >> freebsd-hackers@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-hackers >> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org >> " >> >
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