Dell POWERVAULT MD1000 - Manual (Page 13)

A REFERENCE GUIDE FOR OPTIMIZING DELL™ MD1000 SAS SOLUTIONS VER A00
PAGE 13 5/06/2005
External SAS Cables
Depending on the enclosure topology, one or two external SAS cables may be attached between
the host system(s) and the PowerVault MD1000 storage enclosure. SAS cables use four active 3
Gbps SAS lanes in a single cable to deliver an aggregate of 12.0 Gbps connection. All PowerVault
MD1000 SAS cables purchased from Dell have been tested and comply with the ANSI SAS 1.0
standard. Dell supports using only Dell-provided cables.
External SAS Connector Types
SAS uses a 25-pin connector whose specification is governed by the SFF-8470 specification. For
more information, refer to the specification referenced in Appendix A.
Regardless of the topology, the PowerVault MD1000 storage enclosure also provides some
common capabilities as listed below:
Redundancy Capabilities
• Management Redundancy
With two EMMs installed, the PowerVault MD1000 storage enclosure’s internal enclosure
functions on the PowerVault MD1000, such as temperature regulation, LED control, and
alarm control, are maintained in the event of an EMM failure. However, even with dual
EMMs installed, enclosure status will not be reported to the host in the event of an EMM
failure.
• Power Supply and Cooling Redundancy
The PowerVault MD1000 storage enclosure requires that both power supplies be installed
for normal operation. The system can operate using a single power supply for a limited
time in the event a power supply fails or is removed for service.
The PowerVault MD1000 storage enclosure provides four individually controlled fans, two
installed in each power supply. The unit is thermally designed to continue operating in the
event of one fan blower failure (3+1 cooling redundancy). In the event of a fan failure, the
power supply containing the failed fan must be replaced.