User`s guide

142 XgOS User’s Guide • September 2014
When you bring a vHBA online (up) it will attempt to discover all the attached
targets that are available to it. You can also have the vHBA relearn attached targets
without having to bring the vHBA down, then up. For information, see “Target
Prescan and Rescan” on page 146.
Persistent Binding
A target is a storage device on a SAN. A target can be a single disk, or it can have
many devices (LUNs or volumes) within it.
Users who bind targets to specific devices tend to also specify the scope and search
order (persistent binding) of those devices. In OVN’s application, persistent binding
occurs within a vHBA. When a vHBA becomes active, it is working with many
devices in the network (i.e., switch communication, fabric login, device discovery).
The vHBA then presents this information to the remote OS. In order to preserve the
remote OS’ device-to-drive binding across each bring-up, the persistent binding
setting is required.
By default, no persistent binding is assigned to a vHBA. When persistent binding is
not configured, all the targets found for the vHBA are reported to the remote OS in
a random order (first come first serve). Persistent binding specifies the exact order of
the targets found.
Syntax
add san map <map-name> [<wildcard>] entry <order> <wwpn> [-noconfirm]
add vhba <vhba-name> <card>/<port> -map=<map-name>
show san map <map-name> [<wildcard>]|<map-name> entries
show vhba <vhba-name> [<wildcard>] -map=<map-name>
remove san map <map-name> [<wildcard>] [entry <order>]