On Thu, 2021-02-04 at 08:34 +0100, Hannes Reinecke wrote:

On 1/29/21 10:15 PM, Martin Wilck wrote:

quoted

On Fri, 2021-01-29 at 13:11 -0800, Sagi Grimberg wrote:

quoted

quoted

quoted

quoted

If it does, it will recreate discovery controllers for
every
host_traddr/traddr/trsvcid tuple it finds. "--keep"
semantics
are
only
necessary for addresses on which no regular (non-discovery)
connection
exists.

Wait, Maybe I'm missing something here, but are you saying
that
for
every traddr/trsvcid it finds (both nvm and discovery) it
will
attempt
to connect a discovery controller?

If so, this is absolutely wrong.

Currently, it tries to do that on startup, if (and only if) the
--startup option is given. My expectation was that the
connection
attempts would simply fail if there was no discovery subsystem
to
connect to. Anyway, it's not the default behavior, and can be
dropped
completely if it's so bad that we shouldn't ever attempt to do
it.

IMO it needs to be dropped. I didn't understand this at first
because
it never even occurred to me that such an assumption can be even
made.

quoted

If the service is started early on during boot, and event-based
discovery works (i.e. we also have the mDNS part in place),
this
won't
be necessary of course.

This isn't necessary regardless. At best the discovery controller
endpoints should be obtained from discovery.conf or equivalent.

Understood.

quoted

I don't even see how does this help in early boot anyways, how
do the existing controllers get connected?

For FC, it works today. You can start the monitor in the initrd, it
will receive the fc_udev_device events, and autoconnect (just like
traditional udev/systemd based discovery). For other transports,
it'd
be more work, as we'd need to do mDNS discovery from an initrd
environment. I wouldn't say it's impossible though.

mDNS isn't related to the initrd, mDNS is for discovery discovery :-)

What I had in mind was booting from NVMeoF (non-FC), without prior
local configuration. That requires "discovery discovery" in the initrd,
and thus making mDNS calls in the initrd.

Regards
Martin



_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme