HP XP P9500 Storage - Manual (Page 139)

Notes on Creating an HDLM Environment
This section provides notes on creating an HDLM environment.
For notes on operating HDLM, see Notes on Using HDLM on page 4-2 .
Notes on Hardware Settings
• The types of HBA that are installed on one host can be mixed. However,
the HBAs connected to an HDLM-managed device must all be of the same
type. Also make sure that the HBA driver versions are the same. If the
types or versions of HBAs connected to the devices for the HDLM-
managed SCSI disks vary, you cannot switch the path when an error
occurs.
• You must not change the vendor ID and product ID of the storage
system.
If you change these IDs, HDLM cannot recognize the storage system.
• Make sure that you start the storage system before starting the host.
• When a device is added to a PCI bus, and the IRQ is shared with the HBA
and other devices, a problem might occur. When adding a device, make
sure that the IRQ is not shared with other devices.
• Note the following in an environment where a host is connected to a
storage system by using a fibre channel switch.
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If the host starts while the path between the fibre channel switch and
the storage system is disconnected, the target ID of the path might
be changed after the host restarts. At that time, the disconnected
path might not be recoverable while the host is running. Also, when
you execute the HDLM command to display the path status, the target
ID of the path before the change might be displayed or the
disconnected path might not be displayed.
In either case, change the disconnected path so that the configuration
is the same as that used when that path operated normally. Physically
restore the disconnected path in the same configuration where it used
to operate normally. If the HDLM device name has been changed,
reconfigure the higher-level program.
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If the zone setting for the fibre channel switch has changed, the
target ID of the path might have also changed. When you execute the
HDLM command to display the path status, the target ID of the path
before the change might be displayed. In addition, the HDLM device
name might be changed after the host is restarted. Check the HDLM
device name after the host is restarted. If the HDLM device name has
been changed, reconfigure the higher-level program.
However, you can avoid the above situations by setting a permanent
target ID for each LU with the HBA driver persistent binding functionality.
For details on whether the persistent binding functionality is supported for
your HBA driver and the setting method, see the manual provided with
the HDLM driver.
• If you created an environment by using the QLogic HBA driver while SUSE
LINUX Enterprise Server 9 is being used, before installing HDLM, make
Creating an HDLM Environment
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Hitachi Dynamic Link Manager User Guide (for Linux(R))