SAN device mapping hints and tips

SAN device discovery and device mapping are supported on Windows, AIX®, and Linux®.

The following items illustrate the advantages of IBM Storage Protect SAN device discovery and device mapping:

IBM Storage Protect can display all the devices on the SAN

The QUERY SAN server command shows all the devices that are seen by the server via all the Fibre Channel host bus adapters (HBAs) installed on the system. The parameters that are shown are device type, vendor name, product model name, serial number, and the device name. If FORMAT=DETAIL is specified for the query, additional information such as World Wide Name (WWN), port, bus, target, and LUN are displayed. This information helps identify all the tape, disk, and data mover devices on the SAN. For AIX, the data mover is not apparent and is not shown.

IBM Storage Protect can update the device path automatically when a device's path changes

IBM Storage Protect does not require persistent binding for the devices it sees through the HBA. Instead, the server uses the SNIA (Storage Networking Industry Association) HBAAPI to discover and obtain the serial number for all the devices on the SAN. It can also determine each device's path. By comparing a device's serial number that is recorded in the IBM Storage Protect database with the serial number obtained from the device in real time, a change in a device's path is detected. If the path was changed, SAN discovery automatically obtains the new path for the device. The IBM Storage Protect database is also updated with the new path information.

The HBAAPI wrapper library is the wrapper that is used by the server to communicate with the SNIA HBAAPI. The HBAAPI wrapper library is installed in the same directory as the IBM Storage Protect executable file (unless the full path is given). The following list shows the HBA wrapper files that are included with the server package (except on AIX):

hbaapi.dll
/usr/lib/libhbaapi.a (provided by AIX with HBAAPI installation)
32-bit: libhbaapi32.so
64-bit: libhbaapi64.so

If any of these files are missing, the ANR1791W HBAAPI wrapper library xxxxxxxxx failed to load or is missing. message is displayed.

Disabling SAN device mapping

Occasionally you must disable SAN device mapping to circumvent or isolate a problem when you are troubleshooting device problems.

Perform the following step to disable SAN device mapping and device discovery:

Issue the setopt SANDISCOVER OFF server command. The setopt SANDISCOVERY commands can be issued as many times as needed.
Tip: Another way to disable/enable SAN discovery is to enter the following option in the dsmserv.opt file:
- SANDISCOVERY OFF disables SAN discovery.
- SANDISCOVERY ON enables SAN discovery.
SANDISCOVERY ON is the default for the AIX, Linux, and Windows platforms.

Platform-specific information: When you are working on your SAN device mapping, it is important that you know your platform-specific information.
AIX: The QUERY SAN command does not show any Gateway devices because Gateway devices are not apparent to AIX.
Linux: There are separate libraries, utilities, and other items for RHEL3U3. To run them, you must also install an Emulex ioctl kernel module in addition to the Emulex driver. Ensure that you load the Emulex driver before you load the ioctl module.; Tip: See the list of supported HBAs and required driver levels by operating system.