[OmniOS-discuss] NVMe interface reliable?

[Eric Sproul]

On Sun, Apr 10, 2016 at 8:54 PM, Geoff Nordli <geoffn at gnaa.net> wrote:
> Is the NVMe interface reliable option now?

I've tested it, and it works great.  However, a possible shortcoming
is that there is currently no hot-swap support for nvme(7D) devices.
This isn't an issue if you're doing the PCIe-card form-factor, as
those generally don't get hot-swapped anyway, but is an issue for 2.5"
disk form-factor devices.  These are physically capable of being
hot-swapped (they use the same SFF connectors as SAS/SATA), and at
least Intel says that their drives are "suprise-hot-plug-ready" [1].
At this time, for any NVMe deployment, plan to shut down the system to
perform drive replacements.

That said, it sounds like a lot of folks are deploying these as cache
and log devices, which is less critical for replacing than primary
storage.

It's unknown at this time whether nvme(7D) will gain hot-plug support.
I'm not aware of anyone working on it (including the Nexenta engineer
who wrote the current driver.)

Eric

[1] http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/333596-hot-plug-capability-nvme-ssds-paper.pdf