HP Hitachi Dynamic Link Manager Software - Manual (Page 31)

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For SUSE LINUX Enterprise Server 11:
open-iscsi
• Storage system
The storage system applicable for an IP-SAN is a Hitachi AMS2000 series
storage system.
Restrictions on using HDLM in an IP-SAN environment
The following restrictions apply when using HDLM in an IP-SAN environment:
• HDLM can only be used in a cluster configuration when it is installed in a
Red Hat Enterprise Linux 6 environment with RHCM.
• The kdump function cannot be used.
LU Configuration
After you have properly installed HDLM, the LU configuration will change as
follows:
Before the installation of HDLM:
The host recognizes that a SCSI device is connected to each path.
Thus, a single LU in the storage system is recognized as though there are
as many LUs as there are paths.
After the installation of HDLM:
An HDLM device corresponding one-to-one with an LU in the storage
system is created at a level higher than the SCSI device.
#
Thus, from the host, LUs in the storage system are also recognized as a
single LU regardless of the number of paths.
#
In addition to the one that indicates the entire LU, a logical device file
for the HDLM device is created for each partition.
An LU recognized by a host after HDLM installation, is called a host LU (HLU).
The areas in a host LU that correspond to the Dev (partition) in a storage
system LU are called host devices (HDev).
On a system using HDLM, the logical device file for the HDLM device is used
to access the target LU instead of the logical device file for the SCSI device.
The following figure shows the LU configuration recognized by the host, after
the installation of HDLM.
HDLM Functions
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Hitachi Dynamic Link Manager User Guide for Linux ®