Sas Disk Enclosures With A Rack-Mounted Ups - HP Integrity NonStop i NS2300 Planning Manual

SAS Disk Enclosures With a Rack-Mounted UPS

In this supported configuration, only SAS Disk Enclosures are protected by the rack-mounted
UPS. The rack(s) with SAS Disk Enclosures and/or Storage CLIMs are supported by one or more
rack-mounted UPS.
Figure 17 shows an example of a supported configuration in a NonStop i system with the left
PDUs connected to the rack-mounted UPS, and the right PDUs connected to the utility power.
The rack-mounted UPS is connected to the utility power.
Figure 17 SAS Disk Enclosures With a Rack-Mounted UPS
When the utility power fails, the NonStop system powers off without an OSM-initiated controlled
shutdown of the I/O operations and processors. Only the products in the rack with the
rack-mounted UPS remain powered on. All completed disk write transactions' data are written
to the disk drive media or the disk drive write cache. The rack-mounted UPS provides the extended
time for the disk drives to transfer the data from their write cache to the media. The rack-mounted
UPS provides extended time for the disk drives to transfer the data from their write cache to the
media preventing loss of data.
Supported UPS Configurations 67