IBM ServeRAID M5025, User Manual

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Summary of the ServeRAID M5025 SAS/SATA Controller Characteristics 1-11
Note: The maximum number of hot spares per array is equal to
the maximum number of physical drives per array.
The controller supports 64-bit logical block addressing (LBA), which
makes it possible to connect a large number of drives to the RAID
controller, directly and through expanders. However, the actual number
of drives that you can attach depends on the limits listed in
Table 1.2
rather than by the actual RAID volume capacity.
The maximum numbers in Table 1.2 depend on how many physical
devices you have connected to the controller. For example, the
maximum number of arrays per controller is equal to the number of
physical disks supported by the controller up to the limit of 16 arrays per
controller. In addition, though you can have up to 16 virtual disks in an
array, and up to 16 arrays per ServeRAID M5025 controller, there is a
limit of 64 virtual disks per controller.
1.6.3 SATA II Features
The following list describes the SATA II features of the ServeRAID
M5025 controller:

Supports SATA II data transfers of 3.0 Gbits/s

Supports STP data transfers of 3.0 Gbits/s

Provides a serial, point-to-point storage interface

Simplifies cabling between devices

Eliminates the master-slave construction used in parallel ATA

Allows addressing of multiple SATA II targets through an expander
Maximum hot spares 32
Maximum spans per virtual disk 8
Maximum enclosures per port 9
Maximum ports 2
Table 1.2 ServeRAID M5025 SAS/SATA Controller Array
Limitations
Specification
ServeRAID M5025
SAS/SATA Controller