Grass Valley K2 Summit Storage Area Network v.7.1 - Manual (Page 366)

26 October 2009 K2 Storage Area Network Installation and Service Manual 366
Failover behaviors
K2 client media (iSCSI) connection failover behavior
If the following system connection fails to respond to network communication:
• Media (iSCSI) network “A” connection between a K2 client and the GigE switch.
Then the following failover behavior occurs:
1. The K2 client drops communication on its “A” media port and begins using its “B”
media port and the “B” media (iSCSI) network. The iSCSI adapter (TOE) on the
“B” K2 Media Server provides access to the Fibre Channel connected RAID
storage.
2. Control traffic keeps using the same path to K2 Media Server “A”.
3. K2 Media Server “A” is still the media file system/metadata server. The media file
system (SNFS) and media database do not fail over.
4. The other K2 clients (not affected by the component failure) keep using the same
paths for media and control, as in the previous diagram “Pre-failover behavior” .
This means the K2 clients unaffected by the failover are using the iSCSI adapter
(TOE) on the “A” K2 Media Server to provide access to the Fibre Channel
connected RAID storage, while at the same time the affected K2 clients are using
the iSCSI adapter (TOE) on the “B” K2 Media Server to provide access to the Fibre
Channel connected RAID storage. In this case both RAID controller are
simultaneously providing disk access.
K2 RAID
K2 Media
Servers
K2 client
Gigabit
Ethernet
switches
A
A B
B
Fibre Channel
connections
Control
Media
Control
Media
Control
FTP
Media
Media
! K2 S A S S T O R A G E
! K2 S D I M E D I A C L I EN T
K2 M E D I A S E R V E R
Control
FTP
Media
Media
K2 M E D I A S E R V E R
ISLs
X
Connection
Failure
Control traffic goes
to server A, which is
still the media file
system/database
server.
iSCSI traffic uses
the iSCSI adapter
on server B.