Dell Emulex Family of Adapters - Manual (Page 1209)

OneCommand Manager for VMware vCenter Version 10.2 User Manual P010089-01A Rev. A
6. Managing Adapters and Ports
Viewing and Managing FC/FCoE LUNs
1209

SCSI OS LUN – The SCSI identifier used by the operating system to map to the
specific LUN.

OS Device Name – The name assigned by the operating system to the LUN.
LUN Capacity Area
LUN capacity information is only provided when the LUN is a mass-storage (disk)
device. Other devices such as tapes and scanners do not display capacity.

Capacity – The capacity of the LUN, in megabytes.

Block Size – The length of a logical unit block in bytes.
Enabling an Optimized Access Storage (ExpressLane) LUN
Notes

Enabling an ExpressLane LUN is supported only for the LPe16000 and
OCe15100 families of adapters.

Express Lane is supported only on ESXi5.5 versions.

An ExpressLane LUN must be enabled in the driver before it can be used by the
OneCommand Manager for VMware vCenter. Additionally, the priority value
to mark each of the ExpressLane frames needs to be specified to the FC/FCoE
driver through new driver parameters.

ExpressLane is not supported for LUNs attached to virtual ports.
If your system contains flash and rotational storage I/O on the same initiator port, the
improved performance of the flash storage can be hindered by the slower rotational
storage I/O performance. Because both are sharing the same queue, rotational storage
I/O requests queued up in front of flash storage I/O requests can prevent the
performance gains of flash storage I/O (i.e. head of line blocking). To prevent this, you
can create a separate priority queue in the driver to process the requests ahead of the
normal queue. Additionally, the I/O frames placed on this queue can be marked with a
priority so that the switch and target also prioritizes the flash I/O requests. By
indicating to the FC/FCOE driver, which LUNs should receive this special priority
queuing (i.e. ExpressLane LUNs), performance on these LUNs can be greatly
improved. Even if only FC flash storage is available on your system, there may be
LUNs that you want to run I/O with a higher priority than other LUNs.
To enable an ExpressLane LUN:
1. Select a host in the vSphere console tree-view and select the Emulex OneCommand
tab.
2. In the Emulex Device Management tree-view, expand the FC/FCoE adapter port.
3. Expand the FC/FCoE target.
4. Right-click the LUN on which you want to enable ExpressLane.
5. Select Enable ExpressLane LUN from the pull down menu.