Installing PowerPath on an Linux Host

 

Topic

Setting up a host environment

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Select a host: Linux

Select a Linux task: Installing PowerPath

 

 

Contents

·             Installing PowerPath software on a Linux host 3

 


 

1

·        Installing PowerPath software on a Linux host

 

Overview

This procedure describes how to install PowerPath on a Linux host.

 

Note: This procedure is specific to the installation of PowerPath version 4.5.x, which is the current shipping version for Linux hosts.  For instructions on installing other versions of PowerPath, refer to the applicable PowerPath installation manual available on PowerLink.

 

This procedure is based on content from the following EMC manual:

  • PowerPath for Linux Installation and Administration Guide

 

You can download the guide from EMC Online Support (registration required): https://support.EMC.com

 

Verify the following prior to the installation of PowerPath:

 

·         Review the patch ReadMe files to determine which patches (if any) you want to install after PowerPath, and whether those patches have any added prerequisites that must be met before you install PowerPath.

·         Determine if the PowerPath software you are installing requires the removal or presence of a previous version of PowerPath.  Some full versions require the previous version to be removed while others do not.  Also, some patches require the full version to be present while others require it to be removed.  Refer to the PowerPath Release Notes and/or PowerPath patch readme files for your specific version to determine what needs to be present/removed and if and when a reboot is necessary in order to install your specific PowerPath software version and/or patch.  These documents are available on http://Powerlink.EMC.com.

 

·         For RHEL 3.0 and for all SuSE SLES 8 distributions, verify you have 256 sd and sg devices in the /dev directory.  This prerequisite is required even if the devfs file system is mounted over /dev.

·         Ensure that the PowerPath driver’s major numbers (232-247) are not already in use. If the major numbers are already in use, the driver fails to install at system boot time and issues the following error:

emcp: Device or resource busy


·         Ensure that there is only one path (physical connection) per logical device.

 

 

1.   

Mount the PowerPath CD-ROM or grab from  website:

Install PowerPath software as follows:

 

a.     Verify that you are logged in as root.

b.    Perform the applicable substep:

·         To install from a CD-ROM: 

Insert the PowerPath installation CD-ROM and create the directory /cdrom to be the mount point for the CD-ROM by entering:

mkdir /cdrom

Mount the PowerPath CD on /cdrom by entering:

mount -o ro /dev/cdrom /cdrom

Change to the directory for your operating system:

For SLES, enter: cd /cdrom/LINUX/2.6/pp4.5.x/sles

For RHEL and Asianux, enter: cd /cdrom/LINUX/2.6/pp4.5.x/rhel

·         To installing from a compressed archive:

Download the PowerPath 4.5 archive from http://powerlink.emc.com Resources/Tools CS Support Downloads and Patches Downloads D-R PowerPath for Linux.  Untar the PowerPath archive by entering:

tar -xzf EMCpower.LINUX.4.5.<
release>.tar.gz

 

 

2.   

Install PowerPath

Install the PowerPath software as follows:

 

c.      Install PowerPath by entering the following command:

rpm –i EMCpower.LINUX-4.5.<release>.<package>.rpm

where <package> is:

Package Name

 

Description

sles.x86_64

 

PowerPath 4.5.x on SLES x86_64 platforms.

sles.ia64

 

PowerPath 4.5.x on SLES IA64 platforms.

sles.i386

 

PowerPath 4.5.x on SLES i386 platforms.

rhel.x86_64

 

PowerPath 4.5.x on RHEL and Asianux x86_64 platforms.

rhel.ia64

 

PowerPath 4.5.x on RHEL IA64 platforms.

rhel.i386

 

PowerPath 4.5.x on RHEL and Asianux i386 platforms.

 

 

 

3.   

Register PowerPath

After the installation completes, you must register PowerPath on the host:

 

a.      Locate the PowerPath License Key Card, delivered with the PowerPath media kit, which has your license registration key printed.  

b.   Enter the following command:

/etc/emcpreg –install

c.      At the prompt, type y and press Enter.

d.      At the registration key prompt, enter the PowerPath registration key and press Enter. 

If you enter a valid registration key, you see a success message.

WARNING:  Failing to enter a registration key will result in the installation of PowerPath SE, which is the default policy without a valid PowerPath license.  If you failed to enter the registration key during installation, it can be entered at a later point.

e.   Press Enter and you will see the following output:

1 key(s) successfully registered.

f.            Start PowerPath by entering:

/etc/init.d/PowerPath start

Note:  Use only the above script for EMC PowerPath module loading and unloading.


 

4.   

Post activities

After PowerPath is registered on the host, perform the following:

 

a.      Unmount the CD-ROM by entering:

cd /
unmount /cdrom


b.      Remove the CD-ROM from the CD-ROM drive.

 

c.      Verify the PowerPath capabilities are correct:

 

Enter the following command and verify the output displays the correct load balancing and failover policies.

 

powermt display dev=all

 

Note:  If the load balancing policy does not match your expectations for your license level, check the license registration.  Refer to the man pages for the emcpreg and powermt utilities for clarification on licenses and load balancing.

 

 

5.   

Check for patches

If necessary, install any PowerPath patches from the following URL:

 

    http://Powerlink.EMC.com

 

Note:  A readme file that explains how to install the patch accompanies every patch release.  This file will also state whether you need to reboot the host after the installation of the patch.

 

 

6.   

Make paths visible

The operating system must recognize new paths before PowerPath can. Enter the command:

The operating system must recognize new paths before PowerPath can do so.

 

a.     Stop all running applications, unmount any mounted filesytem.

b.    Run /etc/init.d/PowerPath stop to stop PowerPath.

c.     Unload the HBA driver module. Run rmmod <module_name>, where <module_name> is qla2300, lpfc, or some other value depending on the HBA used.

d.    Reload the HBA driver module. Run modprobe <module_name>, where <module_name> is qla2300, lpfc, or some other value depending on the HBA used.

e.     Run /etc/init.d/PowerPath start to start PowerPath.

 

 

7.   

Configure PowerPath

Configure PowerPath by running:

 

powermt release

 

then

powermt config

 

 

 

8.   

Check the configuration

Inspect the new PowerPath configuration as follows:

powermt display dev=all.

 

The new path(s) should be displayed with a state of alive.

 

Verify that each HBA sees only the targets (FAs) to which it is zoned.

 

Scan operating system error logs to ensure no errors are logged against the new paths.

Correct any issues detected.

 

9.   

Save the configuration

Save the configuration by running the following command:

 

powermt save

 

 

10.  

Check for missing PowerPath devices

If you must, check for missing PowerPath devices using the following command:

 

powermt display dev=all

 

 

11.  

Configure missing devices

Examine the output to determine if some storage system logical devices are not configured as PowerPath devices.

 

Enter the following commands to configure any missing devices:

 

powercf –q
powermt config

Rerun the powermt display dev=all command to confirm the following:
 

· the logical devices are configured as emcpower devices and the correct failover and load balancing policy is set.

· the expected LUNs are visible and each has the expected number of paths.