Notes On Creating An Hdlm Environment; Notes On Hardware Settings - Hitachi XP P9500 User Manual

3.5 Notes on Creating an HDLM Environment

This section provides notes on creating an HDLM environment.
For notes on operating HDLM, see 4.1 Notes on Using HDLM.

3.5.1 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.
• 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.
• 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.
3. Creating an HDLM Environment
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