Storage Multi-Pathing choices in HP-UX Serviceguard environments, August 2009

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since they are tightly integrated with the array vendor’s storage systems, their support is often limited
to only that vendors storage arrays.
HP StorageWorks SecurePath
HP StorageWorks SecurePath for HP-UX is a purchasable software product and the current version
(3.0FSP2 Patch2) provides highly available access to active/active and active/passive HP disk arrays
for HP-UX 11i v2 or earlier. SecurePath provides automatic failover across the paths of the individual
storage device (LUN).
Currently supported active/passive HP StorageWorks arrays:
 EVA 3000 (HSV100)
 EVA 5000 (HSV110)
These arrays are only supported in Serviceguard clusters, if SecurePath is being used. For
active/passive arrays, SecurePath facilitates load balancing and controller failover/failback on
active/passive arrays.
For active/active HP arrays SecurePath provides automatic load balancing across the paths of the
storage device and thereby improves the I/O throughput.
Currently supported active/active HP StorageWorks arrays:
 EVA3000 (HSV101); EVA5000 (HSV111)
 EVA4x00; EVA6x00; EVA8x00
 XP256
 XP48; XP512
 XP128; XP1024
 XP10000; XP12000
 XP24000
After installing SecurePath, the normal device files in /dev/dsk/ and /dev/rdsk become path
independent. For example if a LUN is accessible through two paths (/dev/dsk/6t0d0 and
/dev/dsk/8t0d0) it does not matter which path is specified by the application for the I/O request,
SecurePath will make sure that the I/O reaches the device, even if the request was issued to a failed
path.
HP StorageWorks SecurePath for HP-UX v 3.0F SP2 introduced virtual device special files (Vdsf) for
active/active arrays which can be created for each LUN under its control. Those Vdfs’s are created in
the directory /hpap/dsk/ for block access and in the directory /hpap/rdsk/ for raw access.
Figure 4 shows how to map SecurePath Vdsf to path representing OS device files. In this example, the
Vdsf is: /hpap/dsk/hpap1.
Figure 4: SecurePath Vdsf to path mapping for a specific LUN
# autopath display -l 50_0-2747-0301
==================================================================
HPswsp Version : A.3.0F.02F.00F
==================================================================
Array WWN : 1005-5
==================================================================
Lun WWN : 50_0-2747-0301
Virtual Device File : /hpap/dsk/hpap1
Load Balancing Policy : No Load Balancing
Lun Timeout : Infinite Retry (-1)
==================================================================
Device Path Status
==================================================================