Bug 1718422

(In reply to Tomas Capek from comment #0)
> From: Don Bayly <dbayly>
> Date: Fri, Jun 7, 2019 at 8:27 AM
> Subject: How do I get this added to RHEL 7 and 8 Documentation
> To: Jana Wirch <jwirch>
> 
> 
> We need to get this added to our DOC;s
> ------------------------------------
>   Please Feel free to reword  this as necessary, but this has been verified
> with Engineering and Certification teams. Intel is requesting we make a
> specific statement on Memory Mode. This would be for 7.6 and 8.1
> ===================================

I've edited the draft to be usable as a release note.

A couple of things that I'd like somebody to clarify:

> Red Hat fully supports Memory Mode for DC Optane Persistent Memory
> technology.

Do we support any other modes? Are there any? Or does this simply mean that we support Optane DC as such?

> Intel Optane DC Persistent Memory devices provide data center-class
> persistent memory technology, which can significantly increase transaction
> throughput.
> 
> To use the Memory Mode technology, Red Hat needs no special changes in OS.

I assume this means that you can just connect the hardware and you don't have to configure anything. "Changes in the OS" sounds like adjusting kernel code, though, which I don't think is the case.

> Red Hat also does not call out for any specific certification to support
> Memory Mode.

"Certification" is related here to the system (the hardware, probably), not to the sysadmin, as in e.g. RHCSA, right?

Hi Jeff,

Could you please review the release note in the Doc Text?

I have a couple of questions about it in comment#1.

Thanks!

"To use the Memory Mode technology, you do not have to apply any specific configuration. Your system does not require any specific certification to support Memory Mode."

I'm not sure what you mean by "you do not have to apply any specific configuration."  The NVDIMMs do have to be configured in order to function in memory mode.  For RHEL customers, this means using whatever means is provided by the OSV's pre-boot environment.

(In reply to Jeff Moyer from comment #3)
> "To use the Memory Mode technology, you do not have to apply any specific
> configuration. Your system does not require any specific certification to
> support Memory Mode."
> 
> I'm not sure what you mean by "you do not have to apply any specific
> configuration."  The NVDIMMs do have to be configured in order to function
> in memory mode.  For RHEL customers, this means using whatever means is
> provided by the OSV's pre-boot environment.

Thanks for the review.

The "you do not have to apply any specific configuration" part is a rewrite of "To use the Memory Mode technology, Red Hat needs no special changes in OS" from the original draft. Do you know what "changes in OS" might mean in this context? I interpreted it as Optane-specific configuration, but it could also mean "special drivers" or "kernel modules".

If the sentence is too vague to mean anything, I'll just remove it.

(In reply to Marek Suchánek from comment #4)
> (In reply to Jeff Moyer from comment #3)
> > "To use the Memory Mode technology, you do not have to apply any specific
> > configuration. Your system does not require any specific certification to
> > support Memory Mode."
> > 
> > I'm not sure what you mean by "you do not have to apply any specific
> > configuration."  The NVDIMMs do have to be configured in order to function
> > in memory mode.  For RHEL customers, this means using whatever means is
> > provided by the OSV's pre-boot environment.
> 
> Thanks for the review.
> 
> The "you do not have to apply any specific configuration" part is a rewrite
> of "To use the Memory Mode technology, Red Hat needs no special changes in
> OS" from the original draft. Do you know what "changes in OS" might mean in
> this context? I interpreted it as Optane-specific configuration, but it
> could also mean "special drivers" or "kernel modules".
> 
> If the sentence is too vague to mean anything, I'll just remove it.

OK.  I believe "changes in os" means special driver support.  It may be useful to keep that sentence, but to tweak it so that it is clear that there is no OS configuration necessary.  Memory mode is transparent to the operating system.

(In reply to Jeff Moyer from comment #5)
> (In reply to Marek Suchánek from comment #4)
> > (In reply to Jeff Moyer from comment #3)
> > > "To use the Memory Mode technology, you do not have to apply any specific
> > > configuration. Your system does not require any specific certification to
> > > support Memory Mode."
> > > 
> > > I'm not sure what you mean by "you do not have to apply any specific
> > > configuration."  The NVDIMMs do have to be configured in order to function
> > > in memory mode.  For RHEL customers, this means using whatever means is
> > > provided by the OSV's pre-boot environment.
> > 
> > Thanks for the review.
> > 
> > The "you do not have to apply any specific configuration" part is a rewrite
> > of "To use the Memory Mode technology, Red Hat needs no special changes in
> > OS" from the original draft. Do you know what "changes in OS" might mean in
> > this context? I interpreted it as Optane-specific configuration, but it
> > could also mean "special drivers" or "kernel modules".
> > 
> > If the sentence is too vague to mean anything, I'll just remove it.
> 
> OK.  I believe "changes in os" means special driver support.  It may be
> useful to keep that sentence, but to tweak it so that it is clear that there
> is no OS configuration necessary.  Memory mode is transparent to the
> operating system.

Perfect, thanks. I've edited the release note.

I've also attached the "platform enablement" subsystem for release note tooling purposes.

(In reply to Marek Suchánek from comment #6)

> Perfect, thanks. I've edited the release note.

That looks great, thanks a lot, Marek!