[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Qlogic FC Multipath and engenio

>>>Andrew Miehs <andrew@2sheds.de> 02/01/06 8:52 am >>>
Hi Doug,

Thanks for the quick answer -

Setup is as follows
 * 1 port on Server HBA connected to a switch
 * port 1 from controller A on D240 connected to switch
 * port 1 from controller B on D240 connected to switch
 * LUN1 (disk) default active over controllerA
 * LUN2 (disk) default active over controllerB

What confuses me is NOT that fact that I see both disks twice, (so 
four devices in total)
sdc, sdc, sdd, sde BUT that I can only access two of these - via the 
controller on the storage system.

If I access the 'second path' via the 'other' controller to a disk, I 
get io errors...

Is this normal? I was expecting that all controllers offer all disks 
equally, and am
a bit confused about this 'default active' setting...

I has hoping to avoid compiling the RDAC driver from engenio as it is 
for RedHat or Suse, and I now have to go through the Makefile to fix 
it - hopefully
this should be pretty easy... Their RDAC driver seems to use 'MPP' 
for the failover
- whatever this is.... I guess I will work that out in the next 
couple of hours!

Thanks for any suggestions,


On Feb 1, 2006, at 2:39 PM, Doug Griswold wrote:

>You will see at least 2 devices for every one drive depending on 
>your san configuration.  Multipath tools or mdadm can combine these 
>to make one multipath device.   The qlogic driver will do this for 
>you as well.  From what I have seen if you want support from the 
>storage company you should connect the way they specify in their docs.

To UNSUBSCRIBE, email to debian-isp-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
I'm not a san expert but Ibelieve that there are different types of SAN Architectures.  I am familiar with active/active which means it works like you are thinking I believe there is an active/passive or something similiar which means the other lun is only available when the other path fails from the switch.  I would verify this info on active/passive

Reply to: