| Message ID | 20190808175707.9089-1-vishal.l.verma@intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 7d508e385fb51a2bf14492c9d2ae42a50293c92a |
| Headers | show |
| Series | [ndctl,v2] Documentation/namespace-description: Clarify label-less restrictions | expand |
Vishal Verma <vishal.l.verma@intel.com> writes: > In the ndctl-create-namespace (and related) man pages, add a > clarification note regarding some of the restrictions a user may see > when operating on label-less namespaces. > > Link: https://github.com/pmem/ndctl/issues/52 > Reported-by: Jane Chu <jane.chu@oracle.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> > --- > > v2: > - Remove the part about an address abstraction mechanism; It didn't add > any value (Jeff) > - Add an additional sentence about space reclamation semantics (Dan) LGTM Reviewed-by: Jeff Moyer <jmoyer@redhat.com> -Jeff > > Documentation/ndctl/namespace-description.txt | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/Documentation/ndctl/namespace-description.txt b/Documentation/ndctl/namespace-description.txt > index 94999e5..c59fbef 100644 > --- a/Documentation/ndctl/namespace-description.txt > +++ b/Documentation/ndctl/namespace-description.txt > @@ -18,6 +18,15 @@ the kernel's 'memmap=ss!nn' command line option (see the nvdimm wiki on > kernel.org), or NVDIMMs without a valid 'namespace index' in their label > area. > > +NOTE: Label-less namespaces lack many of the features of their label-rich > +cousins. For example, their size cannot be modified, or they cannot be > +fully 'destroyed' (i.e. the space reclaimed). A destroy operation will > +zero any mode-specific metadata. Finally, for create-namespace operations > +on label-less namespaces, ndctl bypasses the region capacity availability > +checks, and always satisfies the request using the full region capacity. > +The only reconfiguration operation supported on a label-less namespace > +is changing its 'mode'. > + > A namespace can be provisioned to operate in one of 4 modes, 'fsdax', > 'devdax', 'sector', and 'raw'. Here are the expected usage models for > these modes:
diff --git a/Documentation/ndctl/namespace-description.txt b/Documentation/ndctl/namespace-description.txt index 94999e5..c59fbef 100644 --- a/Documentation/ndctl/namespace-description.txt +++ b/Documentation/ndctl/namespace-description.txt @@ -18,6 +18,15 @@ the kernel's 'memmap=ss!nn' command line option (see the nvdimm wiki on kernel.org), or NVDIMMs without a valid 'namespace index' in their label area. +NOTE: Label-less namespaces lack many of the features of their label-rich +cousins. For example, their size cannot be modified, or they cannot be +fully 'destroyed' (i.e. the space reclaimed). A destroy operation will +zero any mode-specific metadata. Finally, for create-namespace operations +on label-less namespaces, ndctl bypasses the region capacity availability +checks, and always satisfies the request using the full region capacity. +The only reconfiguration operation supported on a label-less namespace +is changing its 'mode'. + A namespace can be provisioned to operate in one of 4 modes, 'fsdax', 'devdax', 'sector', and 'raw'. Here are the expected usage models for these modes:
In the ndctl-create-namespace (and related) man pages, add a clarification note regarding some of the restrictions a user may see when operating on label-less namespaces. Link: https://github.com/pmem/ndctl/issues/52 Reported-by: Jane Chu <jane.chu@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> --- v2: - Remove the part about an address abstraction mechanism; It didn't add any value (Jeff) - Add an additional sentence about space reclamation semantics (Dan) Documentation/ndctl/namespace-description.txt | 9 +++++++++ 1 file changed, 9 insertions(+)