HP Fibre Channel Fabric Migration Guide

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Fabric Migration Guide
Fabric Device Addressing Changes
Fabric Device Addressing Changes
When you migrate from an existing Fibre Channel private loop
configuration to a switched Fibre Channel fabric configuration, the
hardware path to the attached target devices will change to reflect the
presence of a fabric/switch in the route from the host initiator to the
target device. When the I/O path information to a given disk changes, a
new device file is created for this device.
Your system administrator will need to change the appropriate
configuration files to allow the correct devices to be used by the file
system or application that accesses these disk device files.
NOTE Device file names and iotree paths will change when a fabric switch
replaces a loop.
Device file names and iotree paths will change when you move a target
from one port on a fabric switch to another port on the switch.
Device files and iotree nodes will change if the switch domain changes.
How to Make Configuration Changes
Check all references to device files. The two most common files to check
are:
• /etc/lvmtab
• /etc/fstab
In all cases where you move an LVM device, you can use the vgexport
and vgimport commands to easily migrate existing volume groups. Use
vgexport to export your volume groups before changing your SAN
configuration or installing the switch. Then use vgimport to import your
volume groups using the new device files.
Please refer to the vgexport and vgimport man pages and to the LVM
portions of your administrator’s guides for details.