Dell Emulex Family of Adapters - Manual (Page 863)

Emulex Drivers Version 10.2 for Linux User Manual P010081-01A Rev. A
3. Configuration
Virtual Port (VPort) Configuration
863
/sys/devices/pci00:03/00:03:06.1/host5/vport-5:0-0/host6/rport-6:0-2:
power target6:0:0 uevent
In this example:

There is a new entry in the fc_vports directory for the VPort (vport-5:0-0). The
vport-5:0-0 entry indicates that the VPort was created from host5 and it is the
first (0) VPort to be created on that fc_host.

The new host for the VPort is host6, and it will appear in the usual directories.

There is also a new directory in the bus tree. This new directory indicates that
host6 was created under vport-5:0-0 (which was created from host5).
VPort Configuration Limits
VPort configuration limits are designated as enforced or unenforced. Enforced limits
are limits that the driver enforces and prevents the user from exceeding. Unenforced
limits are limits that the driver cannot enforce, but configurations that exceed them are
unsupported.
The following VPort configuration limits have been tested with and are supported by
the Emulex driver. Configurations that exceed one or more of these limits are
unsupported.

Before the VPort is deleted or the driver is unloaded, I/O devices accessed
through a VPort must be stopped and file systems must be unmounted.

For enterprise-class adapters, the maximum number of VPorts configurable on
a physical port is 64. The hardware allows more than 64 VPorts to be created,
but the driver has only been qualified at 64. For mid-range adapters, the
maximum number of VPorts configurable on a physical port is 16.

The maximum number of LUNs supported on each driver port is 256.

The maximum number of targets supported for each driver port is 255.

The maximum number of driver ports in one zone is 64. This limit is based on
the system’s ability to recover from link events within the time constraints of the
default timers.
The NPIV use-cases that involve virtual server environment include associating
a VPort with a virtual machine, and placing the virtual machine in its own zone.
This results in one VPort per zone. In the case of load balanced environments,
this can increase typically to two VPorts per virtual machine, to a practical limit
of something far less than 50.
In the NPIV cases not related to virtual server environments, zoning is typically
initiator-zoning, again resulting in one VPort, or a low number of VPorts in the
case of load-balancing, within a given zone. If there are too many VPorts within
a single zone, expected behavior includes devices being lost after link events.

The minimum lifetime of a VPort is 60 seconds. There is an unenforced limit of
60 seconds between the creation of a VPort and the deletion of the same VPort.
VPorts are designed to live for a long time in the system, and the creation of
VPorts is asynchronous. This means that a VPort might not be finished with FC
or SCSI discovery when the command to create a VPort is finished.