Users Guide

Step 2: Migrate Existing Storage-Using
Applications
After the installation script has completed collecting your configuration responses, it displays the following output:
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MPIO Device Migration
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Starting service: ehcmd
Starting service: scsi_reserve_eql
Creating initial DM devices
Pausing now to allow for manual block device migration.
In another shell, check the output of 'ehcmcli status' for the device
names that have been created, and migrate all services and applications
to use the new devices before proceeding.
Consult the user guide for further instructions.
Are you ready to continue and enable active MPIO and iSCSI session
management (Yes/No) [No]?
Switch to a new shell instance and enter the following commands to list all currently detected EqualLogic storage volumes:
# ehcmcli status
The Device to mount: line lists the newly created top-tier device node for each volume. For example:
Volume: replicatest
Target name: iqn.2001-05.com.equallogic:0-8a0906-b30e26209-563ccc969074edcc-
volname
Device to mount: /dev/eql/volname
Status: Normal: MPIO is disabled
In the example, you would use /dev/eql/volname as the block device to mount.
Logical Volume Manager Considerations
If you use Logical Volume Manager (LVM) to manage the disk space on your EqualLogic volumes, ensure that LVM points to the top-tier
multipath device with the following steps:
1. As part of the installation, eqltune added filtering rules to your LVM configuration file (/etc/lvm/lvm.conf) to exclude all
EqualLogic lower-tier devices on most simple setups. If your system uses a more complicated filtering setup, you might need to
manually ensure that all devices under /dev/ignore_eql/* are excluded from consideration by LVM. Run pvscan to verify the
filter rules and ensure proper device names are shown for each physical volume.
If duplicate devices are detected, add rules to /etc/lvm/lvm.conf to remove duplicates and ensure that only the MPIO devices of
the format /dev/eql/volume-name are shown.
NOTE:
If you were using Linux native MPIO (multipathd) and LVM continues to use the mpath devices created by
multipathd, add the following rule to your lvm.conf filter to exclude all multipathd devices: r|/dev/mpath/.*|
Do not add this rule if the device is a boot volume, as these filters may not work properly.
2. After pvscan shows the correct devices, run vgchange --refresh to repoint all active logical volumes to the new EqualLogic
devices without service interruption.
Directly Mounted File Systems
If you are using directly mounted file systems instead of LVM, you must manually unmount and remount them using the top-tier multipath
device names. This action will temporarily interrupt any users (including applications and services) of these file systems.
1. Unmount the file systems associated with the EqualLogic volumes.
Migrating to HIT Linux Multipath I/O
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