Compaq ProLiant Clusters HA/F100 Administrator's Manual page 56

2-22 Compaq ProLiant Clusters HA/F100 and HA/F200 Administrator Guide
Failure of the Hub-to-RA4000/4100 Data Path
The second data path (Figure 2-12), from the storage hub to the RA4000/4100,
has more severe implications when it fails. If this data path fails, all clustered
applications become inoperable. Even attempting to fail the applications to
another cluster node will not gain access to the RA4000/4100.
NOTE: This failure scenario can be avoided by deploying the redundant Fibre Channel
loop configuration of the Compaq ProLiant Cluster HA/F200.
ProLiant
Server
Figure 2-12. Hub-to-RA4000/4100 data path
Without access to shared storage, clustered applications cannot reach their data
or log files. The data, however, is unharmed and remains safely stored on the
physical disks inside the RA4000/4100. If a database application was running
when this failure occurred, some in-progress transactions will be lost. The
database will need to be rolled back and the in-progress transactions re-
entered.
Like the server-to-storage hub data path, the Compaq Insight Manager tools
detect this fault, change the RA4000/4100 status to "Failed," and change its
condition to red. The red condition bubbles up through Compaq Insight
Manager screens, eventually to the device list.
RA4000/4100
storage hub
or switch
Interconnect
ProLiant
Server
Corporate LAN