Serial Attached SCSI technologies and architectures, 4th edition

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SATA devices through expanders. SATA scalability in SAS domains depends on this ability to
communicate through expanders.
Internal
Figure 4 shows a topology for internal RAID systems using either SAS or SATA drives. Each drive has
a point-to-point connection to the controller. The controller can support a maximum of eight drives.
Figure 4: A RAID system topology using two internal ports on the controller to provide redundancy for storage
Figure 5 shows another topology for RAID systems that uses an internal port of the SAS controller, an
HP SAS Expander Card, and SAS or SATA drives. The full-height HP Smart SAS Expander card
supports more than eight internal drives on select ProLiant servers when connected to a Smart Array
P410 or P410i controller. The SAS expander card supports up to 24 internal drive bays, and it has a
Mini SAS 4x port for connecting tape drives.