EMC Disks Unclaimed Unknown for one channel- SCSI

[Laurie A. Krumrey]

Hi All,

We have a K360 on HP-UX 11i. We have hooked
our EMC Symmetric box to it. We have dual
channels (dual paths/cables) for disk mirroring
on the EMC level.

Our problem is that my K360 shows the internal
SCSI card EMC disks but not our external
SCSI card.

There are no device files for the 2nd channel
here is an example of my partial ioscan.

Channel 0 works fine and sees all the disks:
disk 29 10/0.8.6 sdisk CLAIMED DEVICE EMC SYMMETRIX

Channel 4 (2nd channel) all disks are unknown:
unknown -1 10/4/12.8.6 UNCLAIMED UNKNOWN EMC SYMMETRIX

We have tried switching cables, moving our
connections on the back of the Symmetrix box
to another SCSI Adapter.

It's strange because it gives all the hardware
addresses for the LUN'S on EMC correctly but
it just can't claim that 2nd channel.

I have rebooted serveral times and have
done #insf -e more times than I want to admit.

When I do the inq script (from EMC) it only
shows Channel 0 for the EMC disks.

I quess the external SCSI card could be
bad but it worked on another server and
it's claimed when I do an ioscan and there
are no SCSI errors in syslog. Actually there
are no errors in syslog.

Any thoughts...
Laurie Krurmey

[Michael Duthie · Accepted solution]

Sounds like a driver problem... My guess is the channel you are having problems with is a FW HPPB card, so you will need to add the correct drivers to the kernel, scsi3, target & disc3.

The internal card is HSC so using tgt & sdisk.

[Sanjay_6]

Hi,

It could be a problem with the SCSI termination.

Just a thought

Thanks

[Deshpande Prashant]

Hi
As far as I know EMC h/w eng. need to set the EMC box for alternate links. For EMC level mirroring you don't need more fiber paths.
Usage of multiple paths to EMC box can be used either for alternate links or for load balencing and fault tolarence by using EMC software Power Path.
As the inq software is not showing disks on second path, check with EMC for proper configuration. Normally I have seen only after disks are seen by inq command, unix (ioscan) discovers them.
Try ioscan followed after insf -e command just to see if the devices become claimed at ioscan.

Thanks.
Prashant Deshpande.

[Alan Riggs]

I think Mike had the answer. This is most likely a driver problem. Since all of teh hardware paths are populating, the server is actually connecting to the EMC out that path and it is seeing the disk ID's presented to the Symmetrix port. It just cannot identify the devices. Look at the driver and any driver patches.

It is also correct that EMC mirroring is independent of a second connection from the HP. The second connection is used either to provide a "shadow path" for redundancy in case of card failure or to load balance with EMC's PowerPath software.

[Laurie A. Krumrey]

I have all the drivers (scsi3, etc) installed
and claimed. No SCSI connections need to be
terminated because I am trying to use both
of them.

It's still a problem. Are there any patches
I need for 11i?

Laurie

[John Poff]

Hello,

Here's a crazy idea: Could somebody have disabled the director switch for that card on the front of your EMC array?

JP

[Deshpande Prashant]

Hi
If the inq output is still not showing those devices, I"ll first check with EMC.

Prashant Deshpande.

[Alan Riggs]

Please attach ioscan -fnC disk and syminq (should be under /usr/symcli/bin) outputs from both machines.

[Deshpande Prashant]

HI
Your ioscan output matches with inq. 20 EMC disks of 4gb each.
To see unclaimed devices give
#ioscan -fnH 10/4 output

Thanks
Prashant.

[Laurie A. Krumrey]

# ioscan -fnH 10/4

Class I H/W Path Driver S/W State H/W Type Description
==============================================================
bc 3 10/4 bc CLAIMED BUS_NEXUS Bus Converter
tty 0 10/4/0 mux2 CLAIMED INTERFACE MUX
/dev/diag/mux0 /dev/diag/tty0p7 /dev/tty0p1
/dev/diag/tty0p0 /dev/mux0 /dev/tty0p7
/dev/diag/tty0p1 /dev/tty0p0
ext_bus 1 10/4/12 scsi3 CLAIMED INTERFACE HP 28696A - Wide SCSI ID=7
unknown -1 10/4/12.1 ERROR UNKNOWN
unknown -1 10/4/12.2 ERROR UNKNOWN
unknown -1 10/4/12.8 ERROR UNKNOWN
unknown -1 10/4/12.9 ERROR UNKNOWN

[Deshpande Prashant]

Hi
A28696A is a FW differential card.
How about ioscan -H 10/0.

If you have EMC Controle Center, you can load the SymmConsole and take a look at EMC bin file on box to check weather the luns are assigned on both paths.

Prashant.

[Laurie A. Krumrey]

I found a SCSI cumlative patch for 11i release
on 7/13/01 PHKL_24441. I installed this but
it did not make a difference.

Here's the output you wanted:

# ioscan -H 10/0
H/W Path Class Description
=======================================
10/0 ext_bus GSC built-in Fast/Wide SCSI Interface
10/0.1 target
10/0.1.0 disk EMC SYMMETRIX
10/0.1.1 disk EMC SYMMETRIX
10/0.1.2 disk EMC SYMMETRIX
10/0.1.3 disk EMC SYMMETRIX
10/0.1.4 disk EMC SYMMETRIX
10/0.1.5 disk EMC SYMMETRIX
10/0.1.6 disk EMC SYMMETRIX
10/0.1.7 disk EMC SYMMETRIX
10/0.2 target
10/0.2.0 disk EMC SYMMETRIX
10/0.2.1 disk EMC SYMMETRIX
10/0.5 target
10/0.5.0 disk SEAGATE ST34371W
10/0.6 target
10/0.6.0 disk SEAGATE ST34371W
10/0.7 target
10/0.7.0 ctl Initiator
10/0.8 target
10/0.8.0 disk EMC SYMMETRIX
10/0.8.1 disk EMC SYMMETRIX
10/0.8.2 disk EMC SYMMETRIX
10/0.8.3 disk EMC SYMMETRIX
10/0.8.4 disk EMC SYMMETRIX
10/0.8.5 disk EMC SYMMETRIX
10/0.8.6 disk EMC SYMMETRIX
10/0.8.7 disk EMC SYMMETRIX
10/0.9 target
10/0.9.0 disk EMC SYMMETRIX
10/0.9.1 disk EMC SYMMETRIX

[Deshpande Prashant]

Hi
It's strange and confusing, unix is showing devices and inq not. I hoope ioscan -fnH is showing those disks unclaimed as mentioned by you earlier.
So far I had seen inq showing and ioscna takes couple of tries before disks showed up. did you get chanse to speak with EMC? Any luck for EMC controle Center?

Thanks.
Prashant.

[linuxfan]

Hi Laurie,


First of all you did confirm on the EMC side that both the SCSI cards are defined right?

Secondly do you have any other SCSI card on your K360. Can you try that if you have one?

-Ramesh

[linuxfan]

Hi Prashant,

Laurie isn't seeing any disks on 10/4 in the ioscan output, there are 20 EMC disks which are all seen from 10/0 device.

-Ramesh

[Deshpande Prashant]

Thanks Ramesh
Sorry about getting confused on numbers.
In his initial post he seem to see devices unknown on 10/4 path.

Was this scsi channel connected to other device earlier?

EMC need to confirm lun configuration on both channels.

Prashant.

[Laurie A. Krumrey]

OK, I am trying to get a new SCSI card. Do
you think one of the cables could be bad?

I am trying to get with my EMC folks to double
check the SymmConsole stuff.

I think I have the burden of proof.

Laurie

[Deshpande Prashant]

I would suggest to wait for answer from EMC.
EMC can also check the connectivity from disk adaptors on EMC box to host adaptors.

Prashant.

[Alan Riggs]

Please have EMC also check to verify that they have the port on the Symmetrix set for Volume Set Addressing.

[Laurie A. Krumrey]

It was a bad EMC Cable. Thanks for all your
help.

Laurie