Intel JBOD 2000 Family, Руководство по оборудованию

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Intel® Storage Server System JBOD 2000 Family Hardware Guide JBOD 2000 External SAS Connection Mode Overview
Revision 1.42 49
7.6 Dual-port JBOD 2000 External Connection Mode
The Intel
®
Storage System JBOD 2000 dual-port SKU is compatible with the single-port JBOD
2000 connection modes in section 7.5. Besides, dual-port JBOD 2000 can support dual-domain
SAS connection modes. Dual-domain SAS implementations can tolerate the failures of the SAS
controller, external cable, or expander in JBOD 2000. Dual-domain SAS solutions offer higher
reliability, performance, and availability. To take advantage of multiple domains, hard drives
must be dual-ported and connected to pathways in both domains. The SAS drives can meet this
requirement, while the SATA drives usually cannot.
7.6.1 Dual-domain SAS for Dual-port JBOD 2000
Figure 44 shows an example of a 2-connector SAS HBA or RAID adapter capable of dual-
domain support. The connectors of the controller connect to “A PRI” and “A SEC” port on JBOD
2000 with two mini-SAS cables. In the figure, the “4\” notation indicates a 4-lane bundled path.
This dual-domain SAS configuration can tolerate single port failure on the SAS controller,
external cable failure, and failure of the expander in JBOD 2000.
Figure 44. Dual-domain SAS for Dual-port JBOD 2000
The SAS controller in the host can be the single point of failure in the connection mode above.
To avoid this, the second SAS controller can be added in the host. Figure 45 shows an example
of two SAS controllers connecting to the dual-port JBOD2000. The connectors of the first
controller connect to “A PRI” and “A SEC” port on JBOD 2000 with two mini-SAS cables. The
connectors of the second controller connect to “B PRI” and “B SEC” port on JBOD2 000 with
other two mini-SAS cables.
This kind of connection mode can tolerate SAS controller failure but usually needs additional
multipath I/O (MPIO) software support, or using OS native MPIO component. MPIO is a fault-
tolerance and performance enhancement technique when there is more than one physical path
between the host and storage devices through the connection of the buses, controllers,
switches, and bridge devices.
Note: Special FW for the SAS HBA or SAS RAID adapter may be needed for this connection
mode.