topic Missing alternate paths - Mod 20 in Disk Enclosures

Missing alternate paths - Mod 20

John R. Brown — Fri, 13 Sep 2002 17:09:53 GMT

I have a Mod 20 array on a K580 running HP-UX 10.20. The LUN's appear on only one of both hardware paths. We are not seeing alternate paths.
The hardware guys tell me that auto-tresepass is on, but ioscan does not show a second set of addresses. Any suggestions?

Hardware Number Volume Total
Path of Paths Use Group Mbytes Description
10/16/4.0 1 -- -- -- HP Model 20 Disk Array Controller
10/16/4.0.0 1 Unused -- 8013 HP Model 20 LUN (RAID 1/0 -- 4 Disks)
10/16/4.0.1 1 Unused -- 4006 HP Model 20 LUN (RAID 1 -- 2 Disks)
10/4/4.1 1 -- -- -- HP Model 20 Disk Array Controller
10/4/4.1.2 1 LVM vg02 85040 HP Model 20 LUN (RAID 5 -- 6 Disks)
10/4/4.1.3 1 Hot Spare -- -- HP Model 20 LUN (Hot Spare -- 1 Disk)
#
# ioscan -funC disk
Class I H/W Path Driver S/W State H/W Type Description
======================================================================
disk 19 10/4/4.1.0 disc3 CLAIMED DEVICE DGC RAID 10
/dev/dsk/c4t1d0 /dev/floppy/c4t1d0 /dev/rdsk/c4t1d0 /dev/rfloppy/c4t1d0
disk 23 10/4/4.1.2 disc3 CLAIMED DEVICE DGC RAID 5
/dev/dsk/c4t1d2 /dev/floppy/c4t1d2 /dev/rdsk/c4t1d2 /dev/rfloppy/c4t1d2
disk 18 10/16/4.0.0 disc3 CLAIMED DEVICE DGC RAID 10
/dev/dsk/c5t0d0 /dev/floppy/c5t0d0 /dev/rdsk/c5t0d0 /dev/rfloppy/c5t0d0
disk 22 10/16/4.0.1 disc3 CLAIMED DEVICE DGC RAID 1
/dev/dsk/c5t0d1 /dev/floppy/c5t0d1 /dev/rdsk/c5t0d1 /dev/rfloppy/c5t0d1
#
# diskinfo /dev/rdsk/c4t1d0
diskinfo: can't open /dev/rdsk/c4t1d0: No such device or address
# diskinfo /dev/rdsk/c4t1d2
SCSI describe of /dev/rdsk/c4t1d2:
vendor: DGC
product id: RAID 5
type: direct access
size: 87081600 Kbytes
bytes per sector: 512
# diskinfo /dev/rdsk/c5t0d0
SCSI describe of /dev/rdsk/c5t0d0:
vendor: DGC
product id: RAID 10
type: direct access
size: 8205696 Kbytes
bytes per sector: 512
# diskinfo /dev/rdsk/c5t0d1
SCSI describe of /dev/rdsk/c5t0d1:
vendor: DGC
product id: RAID 1
type: direct access
size: 4102875 Kbytes
bytes per sector: 512
#

Re: Missing alternate paths - Mod 20

Ted Ellis_2 — Fri, 13 Sep 2002 18:31:19 GMT

for the paths that do resolve... do they correlate to the primary controllers for the LUN assignments? In other words, for the 2 LUNs that show up under the 4 path... are those assigned to that controller for primary? Is the LUN mapping or assignments set to allow the controllers to share mapping. I am not familiar with this particular array, but we have others from AutoRAIDs to FC60s and MTI.... seems that the server can see both controllers...I am left to target the LUN mapping or configuration. The server seems to have 2 good adpaters, as they each see LUNS... so focus on the array itself and the connections to the server

Re: Missing alternate paths - Mod 20

John R. Brown — Wed, 18 Sep 2002 13:46:37 GMT

Okay -- we found the problem.
The error was caused by the incorrect setting of the SYSTEM TYPE parameter on the SP's. The SYSTEM TYPE must have a value of "2" in order to correctly interface with HP-UX 10.x/11.x systems. Following that change, the second full set of addresses appears for all LUNs.

John