I‘ve CentOS Linux and FreeBSD based server running using 3Ware (9650SE-2LP) RAID card. I know how to check hard disk behind Adaptec raid controllers, but how do I look at ATA / SATA disks behind 3ware SCSI RAID controllers using smartctl command?

You need to use the following device names:
a) IDE / ATA – /dev/hd[a-t]
b) SCSI / SATA – /dev/sd[a-z] OR /dev/twe[0-9] OR /dev/twa[0-9]

HowTo: Look at ATA / SATA Disks Behind 3ware SCSI RAID Controllers

Use the following syntax:

smartctl -a -d 3ware,N /dev/tweY
smartctl -a -d 3ware,N /dev/twaY

The argument 3ware,N, the integer N is the disk number (3ware “port”) within the 3ware ATA RAID controller. The allowed values of N are from 0 to 31 inclusive. You can use the following tw_clin command to find out 3ware port and check RAID card health:
# tw_cli info
Sample outputs:

Ctl   Model        (V)Ports  Drives   Units   NotOpt  RRate   VRate  BBU
------------------------------------------------------------------------
c0    9650SE-2LP   2         2        1       0       1       1      -        

To get port info for c0 controller, enter:
# tw_cli info c0
Sample outputs:

Unit  UnitType  Status         %RCmpl  %V/I/M  Stripe  Size(GB)  Cache  AVrfy
------------------------------------------------------------------------------
u0    RAID-1    OK             -       -       -       232.82    W      ON     

VPort Status         Unit Size      Type  Phy Encl-Slot    Model
------------------------------------------------------------------------------
p0    OK             u0   233.81 GB SATA  0   -            WDC WD2503ABYX-01WE 
p1    OK             u0   233.81 GB SATA  1   -            WDC WD2503ABYX-01WE 

Type the following command to view smart information about the hard disk behind 3Ware RAID card, enter:
# smartctl -a -d 3ware,0 /dev/twa0
# smartctl -a -d 3ware,1 /dev/twa0
Sample outputs:

smartctl version 5.38 [i686-redhat-linux-gnu] Copyright (C) 2002-8 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== START OF INFORMATION SECTION ===
Device Model:     WDC WD2503ABYX-01WERA0
Serial Number:    WD-WMAYP1327617
Firmware Version: 01.01S01
User Capacity:    251,059,544,064 bytes
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   8
ATA Standard is:  Exact ATA specification draft version not indicated
Local Time is:    Sat Jun 25 13:41:26 2011 UTC
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

General SMART Values:
Offline data collection status:  (0x84)	Offline data collection activity
					was suspended by an interrupting command from host.
					Auto Offline Data Collection: Enabled.
Self-test execution status:      (   0)	The previous self-test routine completed
					without error or no self-test has ever 
					been run.
Total time to complete Offline 
data collection: 		 (4080) seconds.
Offline data collection
capabilities: 			 (0x7b) SMART execute Offline immediate.
					Auto Offline data collection on/off support.
					Suspend Offline collection upon new
					command.
					Offline surface scan supported.
					Self-test supported.
					Conveyance Self-test supported.
					Selective Self-test supported.
SMART capabilities:            (0x0003)	Saves SMART data before entering
					power-saving mode.
					Supports SMART auto save timer.
Error logging capability:        (0x01)	Error logging supported.
					General Purpose Logging supported.
Short self-test routine 
recommended polling time: 	 (   2) minutes.
Extended self-test routine
recommended polling time: 	 (  46) minutes.
Conveyance self-test routine
recommended polling time: 	 (   5) minutes.
SCT capabilities: 	       (0x303f)	SCT Status supported.
					SCT Feature Control supported.
					SCT Data Table supported.

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always       -       1
  3 Spin_Up_Time            0x0027   100   253   021    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       7
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002e   200   200   000    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       37
 10 Spin_Retry_Count        0x0032   100   253   000    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0032   100   253   000    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       6
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       5
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       1
194 Temperature_Celsius     0x0022   118   110   000    Old_age   Always       -       25
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   253   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   100   253   000    Old_age   Offline      -       0

SMART Error Log Version: 1
No Errors Logged

SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Short offline       Completed without error       00%        12         -

SMART Selective self-test log data structure revision number 1
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Not_testing
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
Selective self-test flags (0x0):
  After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.

Please note that if the special character device nodes /dev/twa? and /dev/twe? do not exist, or exist with the incorrect major or minor numbers, smartctl will recreate them on the fly. Typically /dev/twa0 refers to the first 9000-series controller, /dev/twa1 refers to the second 9000 series controller, and so on. Likewise /dev/twe0 refers to the first 6/7/8000-series controller, /dev/twa1 refers to the second 6/7/8000 series controller, and so on.

See also:

• Test If Linux Server SCSI / SATA Hard Disk Going Bad
• smartctl and tw_cli man page.