[Ovirt-devel] [PATCH node 6/6] Added new menu for Multipath configuration

[Perry Myers]

On 10/01/2009 11:29 AM, Mike Burns wrote:
> On Wed, Sep 30, 2009 at 09:48:13PM -0400, Andrew Cathrow wrote:
>> so if we're using blacklist exceptions (aka whitelist) then anytime a new lun is provisioned we'd have to edit the multipath configuration. Is that something that we're going to automate in ovirt? 
>>
>> Aic 
>>
>>
> 
> There are a couple of things that we will be looking at to improve this functionality long term.  Functionality in this patch is geared toward being able to install to a multipath device.  There is currently no automated or scripted method for configuring multipath if you are not installing to a multipath device.  I'll be looking at a couple different ways to do this, but haven't settled on a final design yet.  Once I get there, I'll submit a high level design for comments.
> 
> A couple ideas that I'm playing around with:  
> 
> - Breaking off multipath configuration into a separate o-c-multipath script
> - Having a separate script that a user can run that will whitelist a newly provisioned lun.

Using blacklist "*" with specific whitelisted devices
  Pros - Prevents random devices not intended to be monitored by
         multipathd from generating error messages
  Cons - Requires specific addition to whitelist to add a new LUN

Removing blacklist "*" with specific blacklisted devices
  Pros - New LUNs show up automatically
  Cons - Insert a USB stick and it'll generate errors

We could either:

Use the blacklist "*" method and implement a udev hook so that when a new
LUN is attached it causes multipath configuration file change and daemon
restart

Use the whitelist "*" method and find a way to block usb devices somehow
in the blacklist.  This might involve core changes to multipathd.

Perry