MSA2012fc not presenting LUNS on both ports?

[NickBrown]

I'm setting up a simple test lab with a couple ESXi servers - DL360s with a single port FC HBA each - with storage from a single controller MSA2012fc. I've connected port0 on the MSA to the first server HBA and port1 to the second server HBA - no FC switch. As far as I can tell by swapping cables connections around my LUN (volume) is being presented on port0 only. I expected it to be presented on both ports simultaneously - am I missing something obvious?

Cheers, Nick.

[SUBHAJIT KHANBARMAN_1]

Have you checked the HBA of the server where the port1 of the MSA is mapped?

Can you please share the store.logs file ?

[Håkan Persson_1]

Thats how it works, so you can't do it like you try to.
A volume that is "owned" by Controller 1 is presented on Port 1. The other port is for the volumes that failovers from controller 2 (if you have one)

[Håkan Persson_1]

I meant Port 0, to make it more understandable.

[SUBHAJIT KHANBARMAN_1]

Hi Hakan,

I agree with the explanation but that one is applicable when two controllers are present and that is a MSA feature called host port interconnect.

In an FC storage system, the host port interconnects act as an internal switch to provide data-path redundancy.

When the host port interconnects are enabled, port 0 on each controller is crossconnected to port 1 on the other controller. This provides redundancy in the event of failover by making volumes owned by either controller accessible from either controller.

When the host port interconnects are disabled, volumes owned by a controller are accessible from its host ports only. This is the default.

For a single-controller FC system, host port interconnects are always disabled.

But here as per the issue Nick explained I guess issue could be related to HBA or the mapping....I mean need to check port WWN based mapping. Hence requested for the log.

I am sorry if I understand wrongly. May be you can explain better.

[NickBrown]

Subhajit, I've checked the HBA in so far as I know that it works fine when I connect into port0 of the MSA, but not when I connect into port1. How do I get hold of store.logs?

[Johan Guldmyr]

http://bizsupport1.austin.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=120&prodSeriesId=3687115&prodTypeId=12169&objectID=c01907232

[Torsten.]

Did you already check the mapping? If not mapped to that port, you cannot see anything there.

[NickBrown]

@Torsten - yes I have checked the mapping. I've attached store.logs file (had to zip it).

[Torsten.]

What I would do first is this:

Connect to the CLI and run

# show volume-maps

[Torsten.]

What was the status of the servers when you disconnect and connect the cables and how did you test if there is connectivity?

[NickBrown]

@Torsten
# show volume-maps
Volume [SN 00c0ffd5b8e600009b3ed14d01000000, Name (Disk0_V1)] mapping view:
CH ID LUN Access Host-Port-Identifier Nickname
-------------------------------------------------------------------------------
0,1 0 1 rw all other hosts

I tested connectivity by swapping the over cable connections at the MSA end and running a HBA rescan on the hosts. Whichever host is connected to port 0 sees the storage and the host connected to port1 doesn't. BTW the MSA and HBAs are configured to use point-to-point topology (if that's relevant).

[SUBHAJIT KHANBARMAN_1]

I hope this is cluster environment because without cluster is it possible to present a LUN to two different servers ?

You can present but who will be the owner of this LUN at the time of writing when both the servers will try to write.

May be experts can tell on this.

[Johan Guldmyr]

vmfs can handle concurrent writes from more than one host

[NickBrown]

OK it's clear that the port is down which is why I'm not seeing the LUNs, but why?

# show channels
Ctlr Ch Type Media Topo(C) Speed(A) Speed(C) Status PID SID
----------------------------------------------------------------
A 0 Host FC(L) Loop 4G 4G Up 0 1
A 1 Host FC(L) Loop 4G 4G Down
A 0 Drive SAS Up
B 0 Host Down
B 1 Host Down
B 0 Drive Down
----------------------------------------------------------------

Why is my redundancy mode "Active-Active" when I only have one controller? Shouldn't it be "Single-Controller"?

# show redundancy-mode
System Redundancy
-----------------
Redundancy Mode : Active-Active
Redundancy Status : Only Operational
Controller A Status : Operational
Controller A Serial Number: 00C0FFD5B8E6
Controller B Status : Not Installed
Controller B Serial Number: Not Available

Although the web interface seems to contradict this:
"RAID Controller Status: GOOD: Single-controller mode"

??