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.
shows an example of this supported configuration in a NS7 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 22 SAS Disk Enclosures With a Rack-Mounted UPS
When the utility power fails, the NS7 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.
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UPS and Data Center Power Configurations
