Provided by: freebsd-manpages_11.1-3_all 
NAME
twa — 3ware 9000/9500/9550/9650 series SATA RAID controllers driver
SYNOPSIS
To compile this driver into the kernel, place the following lines in your kernel configuration file:
device scbus
device twa
Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
twa_load="YES"
DESCRIPTION
The twa driver provides support for AMCC's 3ware 9000/9500/9550/9650 series SATA controllers.
These controllers are available in 4, 8, 12 or 16-port configurations, and support the following RAID
levels: 0, 1, 10, 5, 50. The device nodes for the controllers are of the form /dev/twaX, where X is the
controller number. The driver is implemented as a SCSI SIM under CAM, and, as such, the logical units that
it controls are accessible via the device nodes, /dev/daY, where Y is the logical unit number.
HARDWARE
The twa driver supports the following SATA RAID controllers:
• AMCC's 3ware 9500S-4LP
• AMCC's 3ware 9500S-8
• AMCC's 3ware 9500S-8MI
• AMCC's 3ware 9500S-12
• AMCC's 3ware 9500S-12MI
• AMCC's 3ware 9500SX-4LP
• AMCC's 3ware 9500SX-8LP
• AMCC's 3ware 9500SX-12
• AMCC's 3ware 9500SX-12MI
• AMCC's 3ware 9500SX-16ML
• AMCC's 3ware 9550SX-4LP
• AMCC's 3ware 9550SX-8LP
• AMCC's 3ware 9550SX-12
• AMCC's 3ware 9550SX-12MI
• AMCC's 3ware 9550SX-16ML
• AMCC's 3ware 9650SE-2LP
• AMCC's 3ware 9650SE-4LPML
• AMCC's 3ware 9650SE-8LPML
• AMCC's 3ware 9650SE-12ML
• AMCC's 3ware 9650SE-16ML
• AMCC's 3ware 9650SE-24M8
DIAGNOSTICS
Whenever the driver encounters a command failure, it prints out an error code in the format: "ERROR:
(<error source>: <error code>):", followed by a text description of the error. There are other error
messages and warnings that the driver prints out, depending on the kinds of errors that it encounters. If
the driver is compiled with TWA_DEBUG defined, it prints out a whole bunch of debug messages, the quantity
of which varies depending on the value assigned to TWA_DEBUG (0 to 10).
AUTHORS
The twa driver and manpage were written by Vinod Kashyap <vkashyap@FreeBSD.org>.