when to use "/dev/nvme0ns1"
ekraju at gmail.com
Mon Dec 7 03:42:58 UTC 2020
Thank you Warner Losh & Yuri Pankov.
Can I use nvmeXnsY for IO?
Looks like fio shows better performance with nvmeXnsY, then nvd/nda devices.
On Sun, Dec 6, 2020 at 11:13 AM Warner Losh <imp at bsdimp.com> wrote:
> On Sat, Dec 5, 2020 at 10:36 PM Yuri Pankov <yuripv at yuripv.dev> wrote:
>> Krishnamraju Eraparaju wrote:
>> > Hi All,
>> > I see there are two ways of accessing NVMe disk:
>> > 1)GEOM based: /dev/nvd0 or /dev/nda0
>> > 2)/dev/nvme0ns1
>> > When should one use " /dev/nvme0ns1"?
>> See nvmecontrol(8) for the commands that operate on namespace ids. And
>> while you could still use nvd/nda devices for those, specifying the
>> namespace explicitly could be helpful.
>> An excerpt from man page:
>> DEVICE NAMES
>> Where ⟨namespace-id⟩ is required, you can use either the nvmeXnsY
>> device, or the disk device such as ndaZ or nvdZ. The leading /dev/
>> is omitted.
> Yes. nvd* and nda* are block devices. nvme0ns1 is for administrative
> things when you may or may not have an nda/nvd device hanging around, or
> you want to deal with a specific thing and don't know the mapping to the
> nda/nvd device.
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