MA6000 HP-UX LUN-id > 7 not seen

[Kurt Beyers.]

Hi,

I've got a MA6000 connected to a HP-UX server (HPUX 11.0). Two new LUN's were defined on the MA6000 array, but a LUN with a LUN-id > 7 was not seen by the HPUX server (ioscan and insf-e discovered only one of the 2 new LUN's that had a LUN-id < 7).

After changing the LUN-id of the other LUN to an id below 7, it was discovered as well by an ioscan.

Are there some patches required or a kernel parameter that must be increased to detect LUN's larger than 7?

regards,
Kurt

[Michael Tully]

Hi Kurt,

HPUX uses a what they call a VBUS (virtual BUS). There is no LUN number defined above 7. They only have a range of 0-7. There is a document I've seen in the forums on this and I have it bookmarked, but I'm not in the office now. If someone doesn't list, I have a look tomorrow morning my time.

There is no patch nor kernel parameter. I know using an EMC array you have to define the VBUS number. Perhaps it is the same with this piece of equipment.

HTH
Regards
Michael

[Vladimir Vybiral]

Hello, HP-UX is a SCSI2 protocol running operating system, so all scsi2 limitations apply - 16 targets per bus, 8 luns per target (0-7) so if there is no patch I would not know about, a lun with a higher number than 7 will not be seen by the OS. On fibre channel systems, there are several ways of going around this - either LUN offsetting as done on HSG controllers, or virtual bus/virtual target/virtual lun as done with VA arrays (this will translate fe. LUN7 and LUN9 into bus0,target0,lun7 and bus0,target1,lun1). BR, Vladimir

[Eugeny Brychkov]

If this MA is FC connected then your issue means it uses Target addressing mode, but not volume set as it should as a disk array.
Please attach 'ioscan -fn' and how MA is connected to the host to your next reply
Eugeny

[Kurt Beyers.]

The MA6000 is fibre attached (with a Compaq switch in between the HP server and the MA6000). There are 2 fibre HBA in the HPUX server and two Compaq switches. The Secure Path software (version 3.0A service pack 1 for HPUX) presents the 4 physical paths to the LUN's as a single logical path

I know that a LUN > 7 on the MA6000 will be translated in a hardware path ctd where z will always be smaller or equal to 7 and that you can calculate out of x, y and z the actual LUN number. My point is that the LUN was not seen when the LUN-id was larger than 7 and was discovered when the LUN-id was changed to a value below 7, nothing on the HP-UX server changed.

Attached is the output of an 'ioscan -fnk' and 'ioscan -fnkC disk'. The Secure Path was still version 3.0 when the ioscan was taken. After the upgrade to Secure Path version 3.0A SP the device files to the disks changed to c14t0d instead of c12t0d. The two new LUN's are not yet in this ioscan but received finally the device files c14t0d0 and c14t0d7.

regards,

Kurt

[Eugeny Brychkov]

I'm right. Target addressing mode. In this mode no more than 8 LUNs. Please attach supportshow output from brocade zipped. I will return here as soon as will have any useful info
Eugeny

[Kurt Beyers.]

Eugeny,

it is a Compaq switch and not a Brocade switch. I'm not managing the switch and a collegue of my didn't know what you mentioned with the showsupport command.

But he said that the problem has to be on the HPUX server, as the LUN was seen after changing the LUN-id on the MA6000.

Can you be pore specific about the information you want?

regards,

Kurt

[Eugeny Brychkov]

I rephrase: is this CPQ switch OEMed from brocade?
I see that MA works in public loop. Is it correct? Why do not you set it up to work in fabric (using MA CLI 'set this
port_1_t = fabric' and 'set this
port_2_t = fabric') and configure it to use SCSI-3 protocol instead of SCSI-2?
Make sure you have latest ACS installed
Eugeny

[Vladimir Vybiral]

Hello Kurt, Eugeny,
Changing to fabric would not solve the situation, it is not tied to the problem Kurt is trying to solve, I think. The question is how to tell HP-UX to use volume set addressing. I am not a HP-UX expert, but You should definitely use SCSI2 mode and CCL (command console lun) presented. Command console lun should be visible to the host as LUN0, so if You create lun0 as a volume, You basically mask it. CCL is used besides other things also for querying LUNs higher than 7. So, I would recommend to check the array is in SCSI2 mode and CCL presented.
Next to Your LUNs 2-6, You should see also 1.16.255.x.y.0 where xy is AL_PA of Your hsg60 ctrl translated and 1.16.zz.0.0.0 CCL device... Once You see this, You have succeeded in switching the VBUS mode on... hmmmm, Vladimir

[Eugeny Brychkov]

Vladimir,
you really know what're you talking about :o)
Kurt,
I've checked with our hpux expert and she said that it's storage device responsibility to tell hpux driver if it's fcparray or fcpdev.
So the items to check are:
1. check for HSG60 to give correct fcparray-capable responce to hpux driver. It usually done by assigning correct OS behavior to host (WWN assigned to 'hpux'). I know HSG80 is capable of it;
2. hpux should have LUN 0, at least virtual one, to query. So please create LUN 0.
Good luck!
Eugeny