Re: [gentoo-user] multipath.conf : learning how to use

["Stefan G. Weichinger" <lists@xunil.at>]

Am 14.08.19 um 13:20 schrieb J. Roeleveld:

> If there is no documentation, it is a mess by definition.

yes :-)

>>>> I see two devices sdc and sdd that should come from the SAN.
>>>
>>> Interesting, are these supposed to be the same?
>>
>> No, I don't think so. But maybe you'r right. No sdd in fstab or in the
>> mounts at all and ...
> 
> See next item, make sure you do NOT mount both at the same time.

I understand and agree ;-)
>> # /usr/bin/sg_vpd --page=di /dev/sdb
>> Device Identification VPD page:
>>   Addressed logical unit:
>>     designator type: NAA,  code set: Binary
>>       0x600605b00d0ce810217ccffe19f851e8
> 
> Yes, this one is different.
> 
> I checked the above ID and it looks like it is already correctly configured.
> Is " multipathd " actually running?

no!

> If it were running correctly, you would mount " /dev/mapper/.... " instead of 
> " /dev/sdc " or " /dev/sdd ".
> 
>> In the first week of september I travel there and I have the job to
>> reinstall that server using Debian Linux (yes, gentoo-users, I am
>> getting OT here ;-)).
> 
> For something that doesn't get updated/managed often, Gentoo might not be the 
> best choice, I agree.
> I would prefer Centos for this one though, as there is far more info on 
> multipath from Redhat.

I will consider this ...

As I understand things here:

the former admin *tried to* setup multipath and somehow got stuck.
That's why it isn't running and not used at all. He somehow mentioned
this in an email back then when he was still working there.

So currently it seems to me that the storage is attached via "single
path" (is that the term here?) only. "directly"= no redundancy

That means using the lpfc-kernel-module to run the FibreChannel-adapters
... which failed to come up / sync with a more recent gentoo kernel, as
initially mentioned.

(right now: 4.1.15-gentoo-r1 ... )

I consider sending a Debian-OS on a SSD there and let the (low
expertise) guy there boot from it. (or a stick). Which in fact is risky
as he doesn't know anything about linux.

Or I simply wait for my on-site-appointment and start testing when I am
there.

Maybe I am lucky and the debian lpfc stuff works from the start. And
then I could test multipath as well.

I assume that maybe the adapters need a firmware update or so.

-

The current gentoo installation was done with "hardened" profile, not
touched for years, no docs .... so it somehow seems way too much hassle
to get it up to date again. Additionally no experts on site there, so it
should be low maintenance anyway.