scsi_vhci(7D)							      Devices							     scsi_vhci(7D)

NAME

       scsi_vhci - SCSI virtual host controller interconnect driver

DESCRIPTION

       The  scsi_vhci  driver  is a SCSA compliant pseudo nexus driver that supports Solaris operating system I/O multipathing services for SCSI-3
       devices. This driver introduces a fundamental restructuring of the Solaris device tree to enable a multipath device to  be  represented	as
       single device instance rather than as an instance per physical path as in earlier Solaris versions.

       The  multipath  SCSI  target  devices managed by this driver are identified and represented by using SCSI-3 VPD page(0x83) as the device's
       unit address.

       Symbolic links in /dev/[r]dsk continue to adhere to the cNtNdNsN format. cN is the  logical  controller	number	assigned  to  this  driver
       instance.  tN is the global unique identifier (GUID) of the multipath target device (64/128 bits), represented as hexadecimal numbers.

       The following is an example of a system with a A5000 storage array:

       ...
	    /dev/rdsk/c4t200000203709C3F5d0s0 -> ../../devices/scsi_vhci/
		      ssd@g200000203709c3f5:a,raw
	    ...
	    /dev/rdsk/c4t200000203709C3F5d0s7 -> ../../devices/scsi_vhci/
		      ssd@g200000203709c3f5:h,ra
	    ...

       The following is an example of a system with a T300 storage array:

	    ...
	    /dev/rdsk/c1t60020F200000033939C2C2B60008D4AEd0s0 -> ../../devices/
		      scsi_vhci/ssd@g60020f200000033939a2c2b60008d4ae:a,raw
	    ...
	    /dev/rdsk/c1t60020F200000033939A2C2B60008D4AEd0s7 -> ../../devices/
		      scsi_vhci/ssd@g60020f200000033939a2c2b60008d4ae:h,raw

       The  scsi_vhci  driver  receives  naming and transport services from one or more physical HBA (host bus adapter) devices. To support multi-
       pathing, a physical HBA driver must comply with the multipathing services provided by this driver.

       The scsi_vhci driver supports the standard functions provided by the SCSA interface.

   Configuration
       The scsi_vhci driver can be configured by defining properties in the scsi_vhci.conf file.

       The scsi_vhci driver supports the following property:

       device-type-scsi-options-list

       To add a third-party (non-Sun) symmetric storage device to run under scsi_vhci (and thereby take advantage of  Solaris  I/O  multipathing),
       you  add  the  vendor  ID  and  product	ID  for  the  device,  as  those strings are returned by the SCSI Inquiry command. As shipped, the
       scsi_vhci.conf file contains, in part:

       # device-type-scsi-options-list =
       # "SUN	  SENA", "symmetric-option";
       # symmetric-option=0x1000000;

       For example,to add a device from a vendor with the ID of "Acme" and a product ID of "MSU", you would add:

       device-type-scsi-options-list =
       "Acme	MSU", "symmetric-option";
       symmetric-option=0x1000000;

       In addition to "Acme," you also might want to add another entry, for example, a device from "XYZ" vendor with a product ID of "ABC:"

       device-type-scsi-options-list =
       "Acme	MSU", "symmetric-option",
       "XYZ	ABC", "symmetric-option";
       symmetric-option=0x1000000;

FILES

       /kernel/drv/sparcv9/scsi_vhci

	   64-bit kernel module (SPARC).

       /kernel/drv/scsi_vhci

	   32-bit kernel module (x86).

       /kernel/drv/scsi_vhci.conf

	   Driver configuration file.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Architecture		     |PCI-based systems 	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWckr			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       eeprom(1M),  prtconf(1M),  attributes(5),  fcp(7D),   fctl(7D),	 fp(7D),   ssd(7D),   scsi_abort(9F),	scsi_ifgetcap(9F),   scsi_pkt(9S),
       scsi_reset(9F), scsi_transport(9F), scsi_inquiry(9S), scsi_extended_sense(9S)

       Writing Device Drivers

       Small Computer System Interface-3 (SCSI-3)

NOTES

       In  previous releases, the scsi_vhci.conf file supported the mpxio-disable  property, which allowed you to disable Solaris I/O multipathing
       on a system-wide basis. This property is not present in the current release of  the  Solaris  operating	system.  Multipathing  is   always
       enabled in scsi_vhci. If you want to disable multipathing, use the mechanisms provided by the HBA drivers. See fp(7D).

       In previous releases, Solaris I/O multipathing was also known as MPxIO and Sun StorEdge Traffic	Manager (STMS).

SunOS 5.10							    2 Dec 2004							     scsi_vhci(7D)