Large SAN storage In larger SAN storage environments where multiple servers access many storage devices,  such as IBM System Storage™ DS devices, through SAN switches, there are dedicated SAN  administrators who manage disk resources. But from an AIX perspective, systems  administrators can help by doing things like choosing multiple dual-port Fibre Channel (FC)  cards to communicate with different fabrics and improve throughput. 7.1.5 LVM configuration With LVM, you can mirror VGs, define a logical volume, and remove a disk with the system  running. Mirroring a logical volume The following scenarios explain how to mirror a normal VG. The following instructions show you how to mirror a root VG by using the System  Management Interface Tool (SMIT): 1. Select a VG in the Volumes container, and then choose  Mirror  from the  Selected  menu.  Experienced administrators can use the  mirrorvg  command. 2. With root authority, add a disk to the VG by using the SMIT fast path that is shown in  Example 7-1. Example 7-1 Extending the volume group by adding a disk for mirroring # smitty extendvg Add a Physical Volume to a Volume Group Type or select values in entry fields. Press Enter AFTER making all desired changes. [Entry Fields]  FORCE the creation of volume group? no + * VOLUME GROUP name [] + * PHYSICAL VOLUME names [] + # smit mirrorvg Mirror a Volume Group Type or select a value for the entry field. Press Enter AFTER making all desired changes. [Entry Fields] * VOLUME GROUP name [] + Example 7-2 Using the mirrorvg SMIT menu 3. Mirror the VG on to the new disk by using the SMIT fast path that is shown in Example 7-2. 4. In the first panel, select a VG for mirroring. In the second panel, define the mirroring  options or accept the defaults. Chapter 7. IBM AIX fundamentals  167