SAN connectivity investigation

Hi All,

I'm a novice when it comes to Linux/Fibre/SAN connectivity and would appreciate some guidance. I inherited 5 Linux systems that are SAN connected andhave been tasked with confirming the setup (i.e. all HBA's are connected, seeing traffic, redundancy, etc). I have researched but have a few questions.

I'll focus on one system for simplicity:

RHEL AS 4.2 (Nahant)
# lspci |grep -i fibre
05:08.0 Fibre Channel: QLogic Corp. QLA2312 Fibre Channel Adapter (rev 02)
06:09.0 Fibre Channel: QLogic Corp. QLA2312 Fibre Channel Adapter (rev 02)

Questions:

- Ideally, I'd like to gather information (lun connectivity, see traffic, HBA state, etc) using Linux native tools as opposed to installing HBA tools.Is this doable or would it be easier or advised to use 3rd party tools for whatever reason? If it is doable, what tools/commands would be recommended? If not, what's the best option?

- I am familiar with device-multipathing. Is it required for multi-HBA redundancy or are there other ways to set up redundancy?

Any guidance or suggestions are greatly appreciated.

TIA,

Herb

On 07/30/2012 04:00 PM, HB wrote:
> Hi All,
>
> I'm a novice when it comes to Linux/Fibre/SAN connectivity and would appreciate
some guidance. I inherited 5 Linux systems that are SAN connected and have been
tasked with confirming the setup (i.e. all HBA's are connected, seeing traffic,
redundancy, etc). I have researched but have a few questions.
>
> I'll focus on one system for simplicity:
>
> RHEL AS 4.2 (Nahant)
> # lspci |grep -i fibre
> 05:08.0 Fibre Channel: QLogic Corp. QLA2312 Fibre Channel Adapter (rev 02)
> 06:09.0 Fibre Channel: QLogic Corp. QLA2312 Fibre Channel Adapter (rev 02)
>
> Questions:
>
> - Ideally, I'd like to gather information (lun connectivity, see traffic, HBA
state, etc) using Linux native tools as opposed to installing HBA tools. Is this
doable or would it be easier or advised to use 3rd party tools for whatever reason?
If it is doable, what tools/commands would be recommended? If not, what's the best
option?
>
> - I am familiar with device-multipathing. Is it required for multi-HBA
redundancy or are there other ways to set up redundancy?
>
> Any guidance or suggestions are greatly appreciated.

Multipathing and RHELAS 4.2... I don't think so. Best bet would be with vendor
supplied tools. Not saying you can't try, but I'd be very surprised if it
worked well.

Because that's such an old (very old) distro (and supported).. you'll find that
the old qlogic drives placed info into /proc/scsi/qla*... so look there for
more info about the card, speeds, etc.

>Multipathing and RHELAS 4.2... I don't think so. Best bet would be with vendor >supplied tools. Not saying you can't try, but I'd be very surprised if it >worked well. Because that's such an old (very old) distro (and supported).. >you'll find that the old qlogic drives placed info into /proc/scsi/qla*... so >look there for more info about the card, speeds, etc.

Chris - Thank you for pointing me in the right direction and yes this system is our oldest..

I see the following in /proc/scsi/qla*

SCSI Device Information:
scsi-qla0-adapter-node=200000e08b85c145;
scsi-qla0-adapter-port=210000e08b85c145;
scsi-qla0-target-0=50001fe150115e4d;
scsi-qla0-target-1=50001fe150115e49;

FC Port Information:
scsi-qla0-port-0=50001fe150115e40:50001fe150115e4d:0a9700:81;
scsi-qla0-port-1=50001fe150115e40:50001fe150115e49:0a1700:82;

SCSI LUN Information:
(Id:Lun) * - indicates lun is not registered with the OS.
( 0: 0): Total reqs 3, Pending reqs 0, flags 0x0, 0:0:81 0c
( 0: 1): Total reqs 8711874, Pending reqs 0, flags 0x0, 0:0:81 00
( 0: 2): Total reqs 158, Pending reqs 0, flags 0x0, 0:0:81 00
( 0: 3): Total reqs 159, Pending reqs 0, flags 0x0, 0:0:81 00
( 1: 0): Total reqs 3, Pending reqs 0, flags 0x0, 0:0:82 0c
( 1: 1): Total reqs 465, Pending reqs 0, flags 0x0, 0:0:82 00
( 1: 2): Total reqs 159, Pending reqs 0, flags 0x0, 0:0:82 00
( 1: 3): Total reqs 158, Pending reqs 0, flags 0x0, 0:0:82 00


SCSI Device Information:
scsi-qla1-adapter-node=200000e08b85003d;
scsi-qla1-adapter-port=210000e08b85003d;
scsi-qla1-target-0=50001fe150115e4a;
scsi-qla1-target-1=50001fe150115e4f;

FC Port Information:
scsi-qla1-port-0=50001fe150115e40:50001fe150115e4a:2a0000:81;
scsi-qla1-port-1=50001fe150115e40:50001fe150115e4f:2a0001:82;

SCSI LUN Information:
(Id:Lun) * - indicates lun is not registered with the OS.
( 0: 0): Total reqs 3, Pending reqs 0, flags 0x0, 1:0:81 0c
( 0: 1): Total reqs 465, Pending reqs 0, flags 0x0, 1:0:81 00
( 0: 2): Total reqs 158, Pending reqs 0, flags 0x0, 1:0:81 00
( 0: 3): Total reqs 159, Pending reqs 0, flags 0x0, 1:0:81 00
( 1: 0): Total reqs 3, Pending reqs 0, flags 0x0, 1:0:82 0c
( 1: 1): Total reqs 469, Pending reqs 0, flags 0x0, 1:0:82 00
( 1: 2): Total reqs 158, Pending reqs 0, flags 0x0, 1:0:82 00
( 1: 3): Total reqs 159, Pending reqs 0, flags 0x0, 1:0:82 00

Can some shed some light on this information or point me to some documentation that I can read to understand it better? I'm assuming that this outputdoes not indicate that redundancy is in place. Can failover be set up (ifone cable is unplugged the other keeps connectivity for the system) in /etc/modprobe.conf?

Sorry for my ignorance, just looking to learn...

TIA,

Herb

On 07/31/2012 12:46 PM, (E-Mail Removed) wrote:
>> Multipathing and RHELAS 4.2... I don't think so. Best bet would be with vendor
>supplied tools. Not saying you can't try, but I'd be very surprised if it
>worked well. Because that's such an old (very old) distro (and supported)..
>you'll find that the old qlogic drives placed info into /proc/scsi/qla*... so
>look there for more info about the card, speeds, etc.
>
> Chris - Thank you for pointing me in the right direction and yes this
system is our oldest..
>
> I see the following in /proc/scsi/qla*
....snip...
not indicate that redundancy is in place. Can failover be set up (if one
cable is unplugged the other keeps connectivity for the system)
in /etc/modprobe.conf?
>
> Sorry for my ignorance, just looking to learn...

No.. this info is just part of what you were asking about, a peek into
data from the driver. I *never* thought of Red Hat as an "enterprise"
player until RHEL 5... even then, it was just their first attempt.

So.. I really don't think multipath works out of the box with RHELAS 4.

Maybe with RHEL 4.5+ (but I don't think so).

Your only hope is vendor supplied tools that might come with
HBA's.. and as a long time Qlogic user, I don't think that's there
either. Sometimes you might get some tools from your storage
provider too (e.g. EMC)... but somehow I doubt they'll give you
something to support something that old now (?? just guessing).

The solution around that time period was still using the multipath
daemon and the device mapper (I think? Not sure about the dm stuff).

But having tested that on SLES 10 (GA) I found it still too risky and
that's 8 mos. after RHELAS 4's first release.