- Sun Storage Virtual Tape Library VTL User Guide

16 VTL User Guide • May 2008 G • 96267
Zoningforhigh‐availabilitysystems
Zoningahigh‐availabilitysystemisslightlymorecomplex thanzoningastandard
system,duetotheneedforredundant path sbetweeninitiatorsandtargets.Once
again,eachSANzonecanhaveonlyoneinitiatorandonetarget.Butthetotal
numberofzonesyouneeddependsonwhethertheSAN
issoft‐zoned(byWorld
WidePortName)orhard‐zoned(byportnumber). See:
■ “WWPNzoning(softzoning)”onpage 16
■ “Portzoning(hardzoning)” onpage 17.
WWPNzoning(softzoning)
Asoft‐zonedSANmapsinit ia tor totargetusingalogicalWorldWidePortName
(WWPN),ratherthanaphysicalhardwareaddress.Thisname‐to‐namezoning
establishesalogicalroutethatmaytraversevaryingphysi cal portsandvarying
physical pathsthroughtheSAN.Toaccomplishfailover,wethusne edonly
asingle
zonefortheclientin it ia tor,theactiveVTL target,andthestandbyVTLtarget.
Seethefigurebelow
shows asoft‐zonedSANbeforeVTLfailover:
Duringfailover,thezonest il lcontainsonlyoneinitia torandonetargetatatime.But
thetargetWWPNisremapped fromaportonthefailedservernodetoaphysical 
portonthestandbyserver.ThestandbyphysicalportspoofstheWWPNofthe
failedport,sozoning
doesnotchange.Thefigurebelowshowsa soft‐zonedSAN 
afterVTLfailover,withastandbyportspoofing theWWPNofthefailedport:
Zone A
T
I
I
Client A
Active VTL server node A
T
I
Standby VTL server node A
SAN
WWPN2
WWPN1
WWPN3
Zone B
I
Client B
WWPN5
WWPN4
WWPN6
Active VTL server node B
Standby VTL server node B