On Wed, 2019-08-28 at 21:16 +0000, Verma, Vishal L wrote:
> On Wed, 2019-08-28 at 13:47 -0700, Scargall, Steve wrote:
> > Hi Jeff,
> >
> > The issue is more of repetition. On an 8-socket system, should a
> > user really be expected to type 'ndctl create-namespace' eight times
> > vs. running 'ndctl create-namespace --region=all' once? SAP HANA is
> > an example app the requires one namespace per region. Scripting is a
> > viable solution, but that requires somebody to write the script and do
> > all the error checking & handling. Each OEM/ISV/SysAdmin would have
> > their own script. Pushing the logic to ndctl seems to be a reasonable
> > approach and let the user handle any errors returned by ndctl.
>
> A scripted solution can indeed be really simple - e.g.:
>
> # while read -r region; do ndctl create-namespace --region="$region";
> done < <(ndctl list --bus=nfit_test.0 -R | jq -r '.[].dev')
>
> {
> "dev":"namespace5.0",
> "mode":"fsdax",
> "map":"dev",
> "size":"62.00 MiB (65.01 MB)",
> "uuid":"c8014457-c268-4f22-8eae-6386fbf08ceb",
> "sector_size":512,
> "align":2097152,
> "blockdev":"pmem5"
> }
> {
> "dev":"namespace4.0",
> "mode":"fsdax",
> "map":"dev",
> "size":"30.00 MiB (31.46 MB)",
> "uuid":"f9498ef6-cdd6-46c7-95f1-86469546ecb9",
> "sector_size":512,
> "align":2097152,
> "blockdev":"pmem4"
> }
>
> > The ndctl-man-page implies the 'ndctl create-namespace --region=all'
> > feature exists today:
> >
> > -r, --region=
> >
> > A regionX device name, or a region id number. The keyword
> > all can be specified to carry out the operation on every region in the
> > system, optionally filtered by bus id (see --bus= option).
> >
>
> This is true, but unfortunately, the implementation has treated create-
> namespace as an exception to this since the start, and I agree with Jeff
> that changing its behavior now can cause other Hyrum's law-esqe [1]
> breakage.
>
> I think however it should be easy to make a compromise, and retain the
> legacy behavior of create-namespace, while creating a new create-
> namespace-greedy command with the new semantics.
>
.. And it doesn't even need to be a new command, a simple --greedy
option to create-namespace should be sufficient.
_______________________________________________
Linux-nvdimm mailing list
[email protected]
https://lists.01.org/mailman/listinfo/linux-nvdimm
