Multipath in HP-UX

[MUDBOY]

Multipath:

A simple example would be a SCSI disk connected to two SCSI controllers on the same computer or a disk connected to two Fibre Channel ports. Should one controller, port or switch fail, the operating system can route I/O through the remaining controller transparently to the application, with no changes visible to the applications, other than perhaps incremental latency.

Features of Multipath:

* Dynamic load balancing
* Traffic shaping
* Automatic path management
* Dynamic reconfiguration

How to find multipath on hp ux ??

1.pvlinks

# strings /etc/lvmtab
# vgdisplay -v vgname

2.Native Multipathing (11.31) (agile device name)

# ioscan -m dsf h/w address

Examble : ioscan -m dsf /dev/rdisk/disk586
Persistent DSF Legacy DSF(s)
=============================================
/dev/rdisk/disk586 /dev/rdsk/c15t0d0
/dev/rdsk/c16t0d0


# scsimgr -D lun_map (which will give the number of paths to that lun)

# ioscan -kfnNC (will show the persistent device file in 11.31)

# evainfo (EVA) and xpinfo (XP) - commands will show the multipaths for luns.