Following the path from HBA to SAN disk...

[Rich Hearn]

Hi All,
I haven't been able to find any info on this, on the web or in the itrc, so I thought I'd give an ask.

The system is 1 node of a 2 node VMS8.3 cluster on 2 ES47s with an EVA5000 for a SAN. We're
using KGPSAs for the fibre channel.

Following the disk path from the O/S HBA (1000-0000-C935-C185) down to the Hrdwr pga

(P00>>>wwidmgr -show wwid -full
pga0.0.0.1.0
- Port: 1000-0000-c935-c185 Dga
pga0.0.0.1.0
- Port: 2002-000d-ec02-b7c0
pga0.0.0.1.0
( Port: 248d-000d-ec02-b7c0
pga0.0.0.1.0
- Port: 1000-00e0-0202-bb27 Mga
- jga22436.13.0.1.0 WWID:01000008:0090-0d26-36b3-6870-0000-0000-0000-0000
- mga26323.13.0.1.0 WWID:01000010:500e-09e0-0005-b7f7-0000-0000-0000-0000
pga0.0.0.1.0
- Port: 1000-00e0-0202-9629 Mga
- jga13140.14.0.1.0 WWID:01000008:0090-0d26-31c1-546b-0000-0000-0000-0000
- mga4987.14.0.1.0 WWID:01000010:500e-09e0-0011-dfc2-0000-0000-0000-0000
- mga28875.14.0.1.0 WWID:01000010:500e-09e0-0011-df9c-0000-0000-0000-0000
pga0.0.0.1.0
- Port: 5000-1fe1-5000-c0fd)

pga0.0.0.1.0
- Port: 5000-1fe1-5000-c0f8

How do I get these two connections (c0fd & c0f8)? From the Switch? Did the KGPSA create these? Am I asking the question correctly?

Thanks,
Rich
_

[Cass Witkowski]

c0fd and c0f8 are from the EVA I would suspect.

[Rich Hearn]

Cass,

thank you for taking the time to give your thoughts. I've been trying to "track" the physical path and these may just be logical.

Tnx agn,
Rich
_

[Cass Witkowski]

To track the physical paths you need to look at the san switches.

[Rich Hearn]

cass,

sorry for the delay... The switches are what got me started on this :^)

I have 2 HBAs in each node (one fibre cable on each). I have 2 switch paths to the EVA (redundency). I'm trying to figure out why I have 4 paths to my Dga disks; 2 on pga0 and 2 on pgb0 and how they get there

[Cass Witkowski]

The EVA has two controllers with two FC connections each. Typically the two switches would be set up in two different SAN fabrics.

The Server has two HBAs. One HBA is connected to switch A and the other to switch B. Each of the EVA controllers are also connected to each switch.

So each HBA can see a connection on each controller. 4 paths

[Mark... · Accepted solution]

Hi,
Useful cmd from VMS to see the paths is:
$ show dev dgaxx/multi
from the o/p if you have two HBA's and a HSV ctrl with four ports and your SAN is configured correctly you should see 4/4 which is your four paths. If any are missing then you should investigate. You should also notice from the o/p that you can see exactly which HBA (pga or pgb) the connection is established with and exactly which port on the EVA is in use for the connection as well.
Look at the last digit of the 16 chars of the WWID.
Example for EVA5000:
WWID of ctrl = xxxx-xxxx-xxxx-xxxx
Ctrl A FP1 = xxxx-xxxx-xxxx-xxx9
Ctrl A FP2 = xxxx-xxxx-xxxx-xxx8
Ctrl B FP1 = xxxx-xxxx-xxxx-xxxD
Ctrl B FP2 = xxxx-xxxx-xxxx-xxxC

To manually move the paths around you can use the "/switch" cmd to move the path from VMS and under CV you can move between ctrl A and B - if you wish.

Mark...

[Robert Badar]

5000-1fe1-5000-c0fd is an EVA port WWID.
On switch You can find e.g. port on which is device with this WWID connected. KGPSA has own WWID.

Regards

[Rich Hearn]

Moderator, I goofed. I should've given 10 pts to Cass (need more coffee)...


Cass,

>The EVA has two controllers with two FC connections each. Typically the two switches would be set up in two different SAN fabrics.

Need to check this - I assume it is

>The Server has two HBAs. One HBA is connected to switch A and the other to switch B.

They are...

>Each of the EVA controllers are also connected to each switch.

I have to go back to my connections for the EVA and see how they are connected - been a long while since I've looked at that. May have to go physically look


Mark, familiar with the cmds - have been handy; it was trying to verify my .coms for switching paths that started me down the road to verifying the physical paths which got me to questioning the 4 "paths" to begin with. I haven't see this stuff in 7 years and wanted to make sure I didn't have anything "crossed" before I shut a path down for upgrading. Nice explanation tho - thank you.

Robert, because I don't use the WWId information often (once every so many years), it's easy for me to "confuse" which WWId is which. I do thank you for pointing that out though.


Thank you Cass, Mark, & Robert for your thoughts & information

Rich