HP HSG Array Controller - Manual (Page 49)

Managing the Switch 3-15
Compaq Confidential – Need to Know Required
Writer: Bill Reitz Project: StorageWorks Fibre Channel Storage Switch User's Guide Comments:
Part Number: AA-RHBYA-TE 135267-001 File Name: d-ch3 Managing the Switch Last Saved On: 4/7/99 11:59 AM
The operating modes are determined by the host adapter. The five operating
modes for the Switch are described in Table 3-4.
Table 3-4
Operating Mode Definitions
Mode Description
0 Normal operating mode, none of the following modes are in effect
1 Tachyon operating mode. Set this mode when there is one or more Tachyon host adapters
connected to the Fabric, and a protocol other than SCSI-FCP is being used over this host
adapter. When this mode is set, multiple Sequences from different sources will be
interleaved to Tachyon at Sequence boundaries rather than at frame boundaries, resulting
in better performance from Tachyon.
2 Isolated operating mode. Set this mode only if the switch’s E_Port discovery process
(transmission of a Class F frame) causes some attached device to fail. When this mode is
set, switches will not join to become a Fabric.
4 No_Probe operating mode. Set this mode only if the switch’s N_Port discovery process
(PLOGI, PRLI, INQUIRY) causes some attached device to fail. When this mode is set,
devices that do not register themselves with the Name Server will not be present in the
Name Server data base.
8 No_MCast operating mode. Set this mode only if buffer-to-buffer credit values greater
than 16 are needed, and broadcast and multicast are not needed. When this mode is set,
the normal range of buffer-to-buffer credit is changed from 1-16 to 1-62 and broadcast
and multicast are disabled.
NOTE: These modes are additive, for example to set a Switch in Tachyon mode and in
No_MCast mode, the operating mode should be set to 9. Any combination of bit maps can
be set up to 16, all values above 16 are ignored.
Virtual Channels
The Switch provides the ability to tune the Switch in a specific application.
The first two virtual channels are reserved for the Switch’s internal functions
and are not available.
NOTE: The default virtual channel settings are already optimized for Switch performance.
Changing the default values, if properly selected, may improve Switch performance
somewhat, but may also severely degrade performance. You should not change these
settings without fully understanding the change’s effects.