nStor 4100FS, User Manual

Page: 90 / 168

Chapter 4 - SAN Solution Strategies
Active-Active:Single Port Mode for SAN
78
Hubs Disabled (Single External Hub)
The following illustration depicts the hosts in a single loop configuration using an
external hub. When a controller failover occurs, this configuration operates much
the same as the previous one which uses a switch. The advantage is that a hub is
less expensive. In Active-Active Dual Port mode, you must manage the multiple
images of the same LUN.
Host 2
FC HBA
Host 1
Hub
FC HBA
Host Link 1
Host Link 2
LUN 1 Passive LUN 1 Active LUN 2 Passive LUN 2 Active
NexStor 4120FS
JFS RAID Controller
SEP
T= Location of internal termination
T T
Controller 1 (A)
SAF-TE Disk I/O
Disk
CH1
Drives 7 - 12
Drives 1 - 6
Disk
CH2
Disk
CH0
Disk
CH3
FC2 FC1
P1 P2
CH 1 CH 2
P3 P4
HOST I/O
JFS RAID Controller
Controller 2 (B)
Disk
CH1
Disk
CH2
Disk
CH0
Disk
CH3
FC2 FC1
T T
T
T
SEP
T T
I/O Card
CH 0 CH 3
Host I/O
Connectors
Disk I/O
Connectors
4100FS.book Page 78 Tuesday, July 8, 2003 4:35 PM