Hi,

after installation multipath-tools does not work properly in order to activate
mapping for devices automagically after the boot.

I finally figured out that

multipath -t >/etc/multipath.conf

generates an initial configuration which is usable, but for a

	find_multipaths "strict"

which is the least friendly way of defining mappings and
practically prevents any auto-mapping (wwids need to be provided by hand).

While that is a perfectly working setup if properly manually configured, for sure it is
not the easiast setting to cope with IMHO.

The final result, for instance, is that LVM could catch all single devices at boot
and the  proper multipaths maps result broken, with the admin not familiar with
multipathd inners lost in the dark.

A very simple configuration such as:

defaults {
	user_friendly_names yes
	find_multipaths yes
}

and a round of update-initramfs after that, gives a proper working implementation, with
LVM perfectly capable of coping with variable names at boot time.

Note that RH folks provides a mpathconf script and an initial template
in /usr/share/doc/device-mapper-multipath-0.4.9/multipath.conf for that.

Hi,

multipath-tools upstream has in the past changed the defaults a
number of times, and I think has now settled on "the best thing to
do is manually configure it, because otherwise lots of edge cases
pop up".

* Francesco P. Lovergine <frankie@debian.org> [230214 09:18]:

Well, it wants you to use the `multipath` program to add a
binding/wwid. This is quite explicit, but also always works.
In my experience, once you leave the realm of test setups, its best
to have explicit configuration.

I'll note that this is a sample for 0.4.9, and this is very old.

Chris

Well, at least some notes about the required manual configuration and steps
to get the wwids (e.g. hinting /lib/udev/scsi_id) and finalize the config,
or even alternative settings would be nice.
I find the README.Debian included not the most clear possible.

That's taken from RHEL 7 documentation, I `suppose` now it is updated.