Ns7 System With Data Center Ups, Both Power Rails - HP Integrity NonStop X NS7 Planning Manual

NS7 System With Data Center UPS, Both Power Rails

In this non-supported configuration, a NS7 system is installed in a Tier-I, Tier-II or Tier-III data
TM
center. The data center tier classification is defined by the Uptime Institute Tier Classifications
Define Site Infrastructure White Paper.
IMPORTANT: If you use this configuration, there is no guarantee your data center will never
lose power.
Figure 24 shows an example of this non-supported configuration in a NS7 system with the left
and right PDUs connected to the data center UPS. In this configuration, OSM does not manage
or monitor the data center UPS.
Figure 24 NS7 System With Data Center UPS, Both Power Rails
When the utility power fails, OSM does not detect that the data center UPS is running on battery
and the UPS has entered its battery runtime. OSM does not initiate the controlled shutdown of
the I/O operations and processors.
If the utility power is not restored before the data center UPS shuts down, any data in the
NonStop X system disk drive write cache that has not been transferred to the disk drive media
is lost.
To prevent data loss during a utility power failure, you must manually disable the Write Cache
Enable (WCE) option on all the disk drive volumes. For information on the WRITECACHE disk
Non-Supported UPS Configurations 87