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LUN Security still showing emulation type in ioscan output

Keith C. Patterson
Frequent Advisor

LUN Security still showing emulation type in ioscan output

I am connected to a 9960 HDS subsystem with an HP host. Although I have secured the LUNS on the port from being seen by the host, the host sees the descriptor field in the output of ioscan. ie.
disk 10 0/4/0/0.1.24.0.0.0.0 sdisk CLAIMED DEVICE HITACHI OPEN-8*4
/dev/dsk/c13t0d0 /dev/rdsk/c13t0d0
disk 12 0/4/0/0.1.24.0.0.1.0 sdisk CLAIMED DEVICE HITACHI OPEN-8*4
/dev/dsk/c13t1d0 /dev/rdsk/c13t1d0
disk 14 0/4/0/0.1.24.0.0.2.0 sdisk CLAIMED DEVICE HITACHI OPEN-8*4
/dev/dsk/c13t2d0 /dev/rdsk/c13t2d0
disk 16 0/4/0/0.1.24.0.0.3.0 sdisk CLAIMED DEVICE HITACHI OPEN-E*2
/dev/dsk/c13t3d0 /dev/rdsk/c13t3d0
disk 22 0/4/0/0.1.24.0.0.4.0 sdisk CLAIMED DEVICE HITACHI OPEN-E
/dev/dsk/c13t4d0 /dev/rdsk/c13t4d0

This last device OPEN-E is the only real device. All other devices are dummy devices that should not be in the list for this path. If you check disk_info all have zero byte capacity except the last one which is the real lun.

I have run the diskinfo command on these devices which returns 0 bytes (what I expect). My question is; is this correct behaviour? I was under the assumption that these devices would show up with "HITACHI DISK SUBSYSTEM" in the output rather than the emulation type which can be rather confusing.
Can anyone address this?
Thanks.
7 REPLIES
Ian Dennison_1
Honored Contributor

Re: LUN Security still showing emulation type in ioscan output

It seems there are 2 questions here,..

a) Why are these disks showing up?

b) Why is the device description showing "OPEN*4" etc?

Answers,...

a) The Disks with cXtYd0 (last digit = Zero) are included as place holders, so that HP-UX can generate the proper cXtYdZ device file. However, because they are not "visible", they return Zero size.

b) Dunno, but have you got the latest Fibre and SCSI patches on the HP Host?

Share and Enjoy! Ian
Building a dumber user
Bernd Reize
Trusted Contributor

Re: LUN Security still showing emulation type in ioscan output

Ian's answer of the first question is perfectly correct.

The 9960 can map these 'LUN 0's as pseudo 'disk subsystem' devices only, if these luns do not exist on its port. If they exits, as in your case (maybe used by other server?) the 9960 uses the description of the real lun for the pseudo devices, too.

Regards, Bernd
Ian Dennison_1
Honored Contributor

Re: LUN Security still showing emulation type in ioscan output

I get the same result when I display my "xpinfoi" output; below is the example of the description being "OPEN-3".

Can I ask what is the desire to see these represented differently?

/dev/rdsk/c11t0d0 0 0 CL2G 1:a7 OPEN-9 0 00059999 0127
/dev/rdsk/c11t0d4 0 4 CL2G 1:54 OPEN-9 7042 00059999 0127
/dev/rdsk/c11t2d0 2 0 CL2G 3:95 OPEN-9 0 00059999 0127
/dev/rdsk/c11t3d0 3 0 CL2G 1:ba OPEN-9*3 0 00059999 0127
/dev/rdsk/c11t4d0 4 0 CL2G 2:1a OPEN-9 0 00059999 0127

Share and Enjoy! Ian
Building a dumber user
Wojciech Kozikowski
Occasional Contributor

Re: LUN Security still showing emulation type in ioscan output

On HP's XP disk arrays (OEMed from HDS) there is special setting (global for whole frame) in firmware to prevent ioscan from showing CLAIMED on ioscan output. Masked LUNs are showed as NO_HW (no hardware) then, e.g.
disk 12 0/2/0/0.1.22.0.0.0.1 sdisk NO_HW DEVICE HP OPEN-E
/dev/dsk/c21t0d1 /dev/rdsk/c21t0d1

I can imagine it should be similar setting for Hitachi arrays too. Ask Hitachi, please -:)

HTH,
Wojtek
Keith C. Patterson
Frequent Advisor

Re: LUN Security still showing emulation type in ioscan output

To Ian's response;
I would like to be able to see the output as "HITACHI DISK SUBSYSTEM" in the output. The reason for this is that there are a number of sysadmins who may be accessing this box at any given time and I don't want any confusion as to which are real and which are Dummy disks.
I wrote a script that checks for 0 byte size in diskinfo output that gets around this.

Thanks all.
Mike Janossy_2
Occasional Visitor

Re: LUN Security still showing emulation type in ioscan output

For the XP (OEM'd from HDS) Secure Manager can protect the LUN by checking every I/O or reporting the device as not present.

The default is to check every I/O, which is likely the situation you find yourself in.

So yes, I think this is normal behavior. If you want to report the device as not present you need your HDS engineer to set a system mode bit (global setting). This may give you what you want but seems quite risky to me.

Good Luck.
Keith C. Patterson
Frequent Advisor

Re: LUN Security still showing emulation type in ioscan output

I have spoken with the HDS rep. and the system option mode is set.
He informed me that this is the way HDS arrays work with HP-UX. It appears as though the description field shows the disk description although LUN security is preventing the actual disk from appearing.
The disk description is stored somewhare is shared memory which is able to penetrate through LUN Security. Not a problem for me though. I just wrote a script to check the filesize of the disk . If 0 bytes, then I flag that as an HDS disk.
Thanks for all responses.