Date: Mon, 22 Oct 2018 09:23:17 -0700 From: Vijay Singh <vijju.singh@gmail.com> To: Alan Somers <asomers@freebsd.org> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: SNIA SDC 2018 recap Message-ID: <CALCNsJRO%2BdkGY30KW-MM2oQ2p3nQjSet7C3hhFZaaQg7NV1b3Q@mail.gmail.com> In-Reply-To: <CAOtMX2hxuLqQFKsO8guaAgNb=3QEZ4VPEq_QW=F0KZF96qYy0g@mail.gmail.com> References: <CAOtMX2hxuLqQFKsO8guaAgNb=3QEZ4VPEq_QW=F0KZF96qYy0g@mail.gmail.com>
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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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