Multipathing with the subsystem device driver

This section provides instructions for installing the multipathing software for the subsystem device driver (SDD).

Ensure that you have followed the steps for preparing and installing the host attachment scripts. See "Host attachment multipathing scripts" for specific instructions.

SDD drivers are provided with the storage unit, but it is advisable to look for the latest version on the Internet. The SDD file sets (nonconcurrent HACMP), readme files and documentation can be found at the following Web site: http://www-03.ibm.com/servers/storage/support/software/sdd. More information about installing and using SDD, see the IBM System Storage™ Multipath Subsystem Device Driver User's Guide.

To verify that you have the latest version of SDD, look on the Internet for the latest version.
1. From the Subsystem Device Driver web page, go to the Download section and select Subsystem device drivers.
2. Choose the appropriate version. Remember that NAS Gateway is AIX powered, so choose Subsystem device driver for AIX.
3. Check the documentation, the “readme” file, and the Web site for prerequisites concerning SDD.
4. You can download the file set to the NAS node with the file transfer program (FTP). Then extract the file set as shown in Figure 1.
  Figure 1. Example of extracting the SDD archive
```
</usr/sys/inst.images>-->tar -xv -f  devices.sdd.52.rte.tar
x devices.sdd.52.rte, 1177600 bytes, 2300 media blocks.
</usr/sys/inst.images>-->_
```
5. Change the directory to cd /usr/sys/inst.images and run the inutoc . exec to create a new .toc file in this directory.
  If you are going to upgrade SDD, refer to the Subsystem Device Driver User's Guide the IBM Enterprise Storage Server and the IBM SAN Volume Controller for details on upgrading to SDD on AIX 5.2.
The following installation guidelines are for a fresh SDD installation only:
1. Ensure that you are logged in as a root user.
2. Issue the following command at a command prompt: smitty install_latest.
3. Choose a period (.) if you changed the directory to /usr/sys/inst.images before. Otherwise, select the directory and press Esc+4 to get to the SMIT install menu.
4. Place the cursor at SOFTWARE to install and press ESC+4.
5. Use the up and down keys to place the cursor to devices.sdd.52 and press ESC+7 to select this SDD file set. The > sign shows the selected item.
6. Press Enter again to return to the SMIT installation menu.
  Note: If you want to do a preview first, select yes in the PREVIEW only? field.
7. Proceed with the installation by pressing Enter. SMIT will ask you to confirm the installation by pressing Enter again. The installation should finish successfully.
8. Verify that the file set is installed by issuing the lslpp -La | grep sdd command. Ensure that the storage unit is correctly configured and attached, and that zoning in your SAN environment is correct. Now you can run the configuration Manager (cfgmgr) on a NAS Gateway 500 command line.
  Attention: Only use the cfgmgr command that is located in the /opt/nas/bin/cfgmgr directory.

If everything is correctly installed, you will see 1750 disks (hdisks and vpath devices with FC2105xxx descriptions) when you run the lsdev -Cc disk command. You can also try the following SDD commands: datapath query adapter, or datapath query device, or lsvpcfg.

After SDD is successfully installed, you can configure VGs, LVs and file systems. Keep in mind that SDD provides new commands like mkvg4vp and extenvg4vp.

Note: You should have only PVIDs on vpath devices (lsdev -Cc disk).