Multipathing to a LUN through brocade switch

Multipathing to a LUN through brocade switch

[Dan Gregory]

Hullo,

I know this list has handle many issues of users not knowing how to
setup multipathing, but I've read all of them and Christophe's wiki and
I can't get my system to talk to my storage array.

OS: RHEL 4.2, device-mapper-multipath-0.4.5-6.0.RHEL4

Configuration:  I have a SunFire 4100 with one 2 port qla hba pci card
dual connected to a single 16 port brocade silkworm which in turn in
dual connected to a Sun StorEdge 3511.  Interestingly, I get 4
/dev/sd[c-f] associated with the same LUN.  I presume that each device
can see the LUN through each of the 2 connections from the switch to the
3511.

I know that mapper is working because there are 2 devices that the LVM
creates, one for / and one for swap, but the LUNs don't show up.
multipath -v2  does not give any output, but -v3 gives information on
all 6 of the sd[a-f] devices.  The only differences in the output of
sd[c-f] are dev_t and h:b:t:l fields (see below).  I've tried to add
entries into the multipath.conf file, but nothing changes the output and
I never get any more devices in /dev/mapper.

What am I doing wrong?


Thanks,
Dan



(I diffed the sections in the multipath -v3 output)

< ===== path sdc =====
---
> ===== path sdf =====
3c3
< dev_t = 8:32
---
> dev_t = 8:80
8c8
< h:b:t:l = 1:0:0:0
---
> h:b:t:l = 2:0:1:0
17,18c17
< path sdd not found in pathvec
<
---
> path sdg not found in pathvec

Re: Multipathing to a LUN through brocade switch

[Dan Gregory]

All,

I fixed my issue with this but it brings up some other problem.  It
turns out that hal installed a non-existent floppy drive as /dev/sdg.
When multipath ran it appeared to "crash" when trying to query this
device.  When I added sdg to the blacklist it worked.

The question now, is there any way that you can blacklist on anything
but the /dev/* names because it would seem that in my case /dev/sdg
could potentially change at some point and my blacklist could block a
legitimate drive.

Thanks,
Dan


Dan Gregory wrote:
> Hullo,
> 
> I know this list has handle many issues of users not knowing how to
> setup multipathing, but I've read all of them and Christophe's wiki and
> I can't get my system to talk to my storage array.
> 
> OS: RHEL 4.2, device-mapper-multipath-0.4.5-6.0.RHEL4
> 
> Configuration:  I have a SunFire 4100 with one 2 port qla hba pci card
> dual connected to a single 16 port brocade silkworm which in turn in
> dual connected to a Sun StorEdge 3511.  Interestingly, I get 4
> /dev/sd[c-f] associated with the same LUN.  I presume that each device
> can see the LUN through each of the 2 connections from the switch to the
> 3511.
> 
> I know that mapper is working because there are 2 devices that the LVM
> creates, one for / and one for swap, but the LUNs don't show up.
> multipath -v2  does not give any output, but -v3 gives information on
> all 6 of the sd[a-f] devices.  The only differences in the output of
> sd[c-f] are dev_t and h:b:t:l fields (see below).  I've tried to add
> entries into the multipath.conf file, but nothing changes the output and
> I never get any more devices in /dev/mapper.
> 
> What am I doing wrong?
> 
> 
> Thanks,
> Dan
> 
> 
> 
> (I diffed the sections in the multipath -v3 output)
> 
> < ===== path sdc =====
> ---
> 
>>===== path sdf =====
> 
> 3c3
> < dev_t = 8:32
> ---
> 
>>dev_t = 8:80
> 
> 8c8
> < h:b:t:l = 1:0:0:0
> ---
> 
>>h:b:t:l = 2:0:1:0
> 
> 17,18c17
> < path sdd not found in pathvec
> <
> ---
> 
>>path sdg not found in pathvec
> 
>