Applies to:

RHEL, OEL 5.7, 5.8

Author:

Carthik Annayan

Problem:

How to configure Multipath Using Equallogic Host Integration Tool Kit (HIT) & on Linux for Oracle?

Solution:

What is Equallogic Host Integration Toolkit (HIT)?

The Equallogic Host Integration Toolkit (HIT) is a collection of applications and utilities to simplify the configuration and administration of Dell Equallogic PS Series Storage Arrays.

Host Integration Tools for Linux provides the following features:

  • Remote Setup Wizard Command Line Interface (RSWCLI) — A setup utility you use to:
  • Discover and initialize PS Series arrays
  • Configure and manage access to a PS Series group
  • Set configuration parameters for Multipath I/O (MPIO)
  • Manage which subnets are used for MPIO
  • Automate iSCSI session management to create and maintain the optimal iSCSI session
    configuration for high availability and increased performance.
  • EqualLogic iSCSI Multipathing — A combination of user and kernel mode binaries that:

Improve I/O performance by intelligently routing I/O directly to the correct PS Series
array member, thereby reducing intra-group I/O forwarding.

Initially, let’s see how to configure the equallogic HIT Kit. Download the Hit Kit (1.1) for Linux. If you have a support ID and Password, download from the below link https://support.equallogic.com/support/download.aspx?id=10235

Installation Steps

To install HIT Kit for Linux, perform the following steps.

Create a directory in which you will mount ISO image:

# mkdir -p /media/iso   –nogpgcheck

Mount the ISO image in the /media/iso directory:

# mount -o loop equallogic-host-tools-version.iso /media/iso

The installation script provides several options for installing under certain conditions. To see these options, enter /media/iso/install --help. To run the installation script for a fresh install, simple enter:

# /media/iso/install

Steps to Discover and Configure the Storage:

First the Equallogic storage should be discovered, in-order to discover the Equallogic storage, use the Remote Setup Command Line Interface (RSWCLI).

Discovering a PS Series Array:

# rswcli –discover –detail

Note: For the Discovery command to work, make sure that your host network is configured in the Storage IP range.

Once the PS Array is discovered, group access should be granted to the group that you would like to access. We use the RSWCLI command to grant the group access.

# rswcli --add-group-access --gn  groupname  --gip groupip

Example #rswcli --add-group-access --gn  hitkitgroup   --gip 192.18.16.50

The next step is to discover the targets.

# iscsiadm -m discoverydb

Use the Below Command to discover new Targets (after the initial discovery):

# iscsiadm -m discoverydb [-I iface] -p group-IP-address -t st -o new –D

# iscsiadm -m discoverydb -p 192.18.16.50 -t st -o new –D

Conditions for Configuring Multipath Devices:

1)      Certain conditions should be met to successfully to configure multipath devices using HIT Kit for Linux. Use of the multipathd Daemon is not required. Do not run this daemon before configuring multipath devices. Use the following command to disable multipath service.

 #chkconfig multipathd off

#service multipathd stop

2)      If you must create, delete, or modify the partition table on a volume, use a partition management utility (for example, fdisk) against the EqualLogic DM devices present under.

 /dev/eql/volume_namep#

where volume_name is the name specified at volume creation and p# is the partition number (for example, p1, p2, etc.)

Logging into a Volume with Multipath I/O:

To login to a volume with multipath we use the ehcmcli commands . These commands are used to simplify login and logout from iSCSI targets. Now let’s see how to login using the ehcmcli commands.

# ehcmcli login --target target_name --portal portal

Note:  # ehcmcli status command displays the status of each volume, the paths its used to login and the target names

Example:

# ehcmcli login --target iqn.2001-05.com.equallogic:0-290c06-52f7c99c6- 1a2000001aa4f479-myvolume

 Login succeeded. Device to mount:

/dev/eql/myvolume

To set a volume for automatic login on the next system startup, use the --login-at-boot option with the ehcmcli login command:

 # ehcmcli login --target target [--portal portal] --login-at-boot

Note:- When configuring, Creating Oracle ASM Disks when using EqualLogic Hit Kit. Please use the devices under the location /dev/eql/device_name.