Sun Microsystems 6900 - Manual (Page 34)

14 Sun StorEdge 3900 and 6900 2.0 Series Troubleshooting Guide • March 2003
Sun Proprietary/Confidential: Internal Use Only
The host, using multipathing software, is presented with two primary (active) paths
for each LUN, allowing the host to route I/O through either or both HBAs.
If a path failure occurs before the second tier of Sun StorEdge network FC switch-8
and switch-16 switches, one of the paths is disabled—but the other path continues
sending I/O as it normally would and takes over the entire load. Refer to
FIGURE 2-4 ,
which illustrates a path failure before the second tier of switches.
No Sun StorEdge T3+ array failure is noted because of the redundant path, by way
of the Sun StorEdge network FC switch-8 and switch-16 switch T ports.
FIGURE 2-4 Path Failure—Before the Second Tier of Switches
LUN0 - 10G
Active-MPDrive 0
LUN1-10G
Active-MPDrive1
LUN0 - 10G
Active-MPDrive0
LUN1 - 10G
Active-MPDrive1
Host with HBA-0 and HBA-1
Switch
Switch Switch
SAN
Database
MPDrive
Carved LUNs
Masking
Virtualization
Engine (2)
LUN0 - 500G
Active-Master
LUN1 - 500G
Passive -
Alternate Master
LUN0 - 500G
Passive-Master
LUN1 - 500G
Active -
Alternate Master
Logical Multipath
Drive MPDrive 0
Logical Multipath
Drive MPDrive 1
T3ES
(Master)(0A - 1P)
(Alternate Master)
(1A - 0P)
Switch
FAILURE
Storage I/O and
Virtualization Engine Communications Traffic