1. AIC/XTORE SAS OVERVIEW
May, 2006
Dale Tsai
Jack Fan

2. What is SAS SAS – Serial Attached SCSI, A natural transition from
parallel SCSI to serial

3. Why Serialize? Signal skew and crosstalk
Signal termination restrictions
Cable and connector reflections
Device addressability

4. Serial Technologies
SAS : 1st gen. 3Gbps

5. SAS Features/Benefits
Performance
3.0Gbps(300MB/s)per single SAS port
Port Aggregation, eg. Combine 4 ports to a single 12Gbps WIDE PORT (x4 port)
Full Duplex (24 Gbps)
Multiple Initiators and Targets (with Expander)
Advanced Command Queuing
Advanced Command queue: just like SCSI supports up to 256 queue levels.

6. SAS Features/Benefits
Flexibility
Coexist of SAS and SATA Drives
SCSI software/middleware can be used
Scalability
Up to 16,256 SAS/SATA devices (in one SAS Domain)
Expander is able to connect 128 devices
Reliability
Dual Port and Multi-initiator for Fault Tolerance
Hot-swap connector
High MTBF Drive
Using SATA: cost-effective bulk storage, to be applied where transaction rates are low and data availability is not critical.
Using SAS: are built for high-performance, high-availability use.
Eliminating new training or integration costs and the need for modifications to legacy software
A Fan out Expander is able connect to 128 devices, including initiators, fan out expanders, edge expanders, and SAS/SATA drives.

7. Interface Comparison ATA SATA SCSI SAS FC Interface Parallel Serial
Addressing 2
1, or 16 with
SATA II 16
128
16 million
Connection
80-pin
7-pin
68-pin Internal/ external
Copper/optical intemal/external
Dual-port No
Yes
Topology
Bus
Point-to-point
Point-to-point w/expanders
Loop, fabric
Duplex
Half
Full
Max.devices
1, or 15 with port multiplier
16,256 With expanders
127-loop 16.7 million fabric
Cable length
0.4m 1m
12m
10m
30m (copper) 300m (optical)
Applications
Internal Storage
ATA RAID, server,and high-end work-station storage
Midrangeand enterprise servers
SAN and enterprise servers

8. Advantage of SAS Interface
High Speed Serial SCSI instead of Parallel
Point-to-Point Connection
Expander for Scalability
Dual Port Connectivity
SATA Compatible Dual 7-pin Interface
Port Aggregation e.g. x4 WIDE PORT

9. Point-to-Point Connection
Server .
Up to 8
HBA (8 ports)
One by one single port connection
Usually for HDD inside server enclosure
Either SAS or SATA drive can be used

10. Expander for Scalability
HBA (8 ports)
Server
HBA (8 ports) 4 4 4
Port Aggregation
X4 Wide port
Dual ports connected
JBOD 1
Use SAS drive for dual, SATA only for single
36 Ports
Expander .
Up to 24
36 Ports
Expander 4
12Gbps 4
Usually used for external connection (JBOD),
but also for internal, sometimes

11. Dual Port Connectivity

12. Dual Port SAS/SATA DesignB A C K P L N E
SAS HBA Port x 1
SAS connector
SAS HDD
SAS HBA Port x 1 B A C K P L N E
SAS HBA Port x 1
1:2
MUX
SATA I/II HDD would need to use an Active-Active port selector
(multiplexer/MUX) to support dual functions in a SAS enclosure.
SAS connector
SATA HDD
SAS HBA Port x 1
SATA connector
Vitesse 7170
PMC xxx
Siliconstor SS1300

13. Failover via Dual Port
cross over
Further
Expansion
Further
Expansion

14. Expander Chips PMC Sierra Vitesse LSI Logic 12-port, P# LSISASx12
12-port, P# PM8383-BI
24-port, P# PM8387-BI
36-port, P# PM8388-BI
Vitesse
12-port, P# VSC7160
24-port, P# VSC7153
36-port, P# VSC7154

15. SAS HBA Chip Vendors: LSI Logic, Adaptec 4 or 8 ports are available
PCI-X (64b x 133) or PCI-E(2.5Gb x n)
Most HBAs now still use PCI-X (~1GB/s)

16. Xtore SAS JBOD with HBA

17. Xtore SAS DAS/JBOD Solutions
3U 16 Drives SAS JBOD
External cable
1U 10 Drives SAS JBOD
Solution1 Elements:
Servers
SAS RAID HBA
Xtore 1U 10 drivers or 3U 16 Drivers SAS/SATA JBOD

18. High-Performance SAS Server Clusters
Xtore SAS JBOD Series
Solution3 Elements:
Servers with support for multi-path I/O (MPIO) support if path failover is required on the same server
Cluster Software -single or dual SAS controllers and cluster software per node in the Cluster
SAS RAID HBAs
Xtore SAS/SATA JBOD series

19. XJ-SA24-316R XJ-SA26-224R XJ-SA26-212R XJ-SA26-110R
SJ-1100 SAS JBOD Series
XJ-SA24-316R XJ-SA26-224R XJ-SA26-212R XJ-SA26-110R

20. Connection for 16 Drives SAS JBOD
3U 16-channel for 16 x 3.5” SAS-SAS/SATA JBOD w/dual-port and daisy-chain support
8-channel SAS controller A
or HBA Card
8-channel SAS controller B
or HBA Card
Redundant PS
4 x A1
4 x B1
SAS 4X A1
SAS 4X Expansion A
24X
exp
16 x
16 x
24X
exp
IO Board A
SAS 4X B1
SAS 4X Expansion B
4 x Expansion B
IO Board B
IOBoard
4 x Expansion A
To Daisy-Chain JBOD enclosure (level 2 to level n)

21. Cont’d Support 3.5” SAS/SATA HDD Dual JBOD Controller SES Compatible
Redundant Power Supply
Dual 4x Host or Single 4x Host + 4x Expansion port
HDD Status LEDs
Hardware Fault Alarm
Windows In-band Firmware Upgrade & Serial Monitoring Console
SES: SCSI Enclosure Services
Dim: 440x546x132.5(mm)

22. XJ-SA24-316R
3U chassis _ 16bays 3.5’’HDD

23. Connection for 2U 2.5”x24 SAS JBOD
2U 24-channel for 2.5” SFF SAS-SAS/SATA JBOD w/dual-port and daisy-chain support
8-channel SAS controller A
or HBA Card
8-channel SAS controller B
or HBA Card
Redundant PS
4 x A1
4 x A2
4 x B1
4 x B2
SAS 4X A1
SAS 4X A2
IO Board A
SAS 4X Expansion A
24 x
24 x
SAS 4X B1
36 X
exp
36 X
exp
IOBoard
IO Board B
SAS 4X B2
SAS 4X Expansion B
4X Expansion A
4X Expansion B
To Daisy-Chain JBOD enclosure (level2 to level n)

24. Cont’d Support 2.5” SAS/SATA HDD Dual JBOD Controller SES Compatible
Redundant Power Supply
Dual 4x Host & 4x Expansion port
HDD Status LEDs
Hardware Fault Alarm
Windows In-band Firmware Upgrade & Serial Monitoring Console
Dim: 440x495x88(mm)

25. Connection for 1U 2.5” x 10 SAS JBOD
1U 10-channel for 10 x 2.5” SFF SAS-SAS/SATA JBOD w/dual-port and daisy-chain support
SAS controller A
or HBA Card A
SAS controller B
or HBA Card B
Redundant PS
4 X A2
4 x B1
4 x B2
SAS 4X A1
4 x A1
SAS 4X A2
IO Board A
SAS 4X Expansion A
24 X
exp
24 X
exp
SAS 4X B1
10 x
10 x
IOBoard
SAS 4X B2
IO Board B
SAS 4X Expansion B
4X Expansion A
4X Expansion B
To Daisy-Chain JBOD enclosure (level 2 to level n)

26. Cont’d Support 2.5” SAS/SATA HDD Dual JBOD Controller SES Compatible
Redundant Power Supply
Dual 4x Host & 4x Expansion port
HDD Status LEDs
Windows In-band Firmware Upgrade
Dim: 440x433.5x44(mm)

27. XJ-SA26-110R
IU chassis_10 bays 2.5’’HDD

28. Xtore SAS JBOD XJ-SA26-110R XJ-SA26-224R XJ-SA26-212R XJ-SA24-316R
Form factor
1U 10-bay
2U 24-bay
2U 12-bay
3U 16-bay
Expander
VSC7153
24-port
　VSC7154
36-port
　VSC7153
Uplink (Host interface)
per IO module
Dual mini SAS, 4x
Dual mini SAS
Single mini SAS
Downlink (Expansion interface) per IO module
(or used as Host)
SAS addresses # 26 38
Route table entries
320
Expansion enclosures # 12 22 17
Vitesse advantages
Integrated Enclosure Management controller
Integrated SSP Initiator and target capability
All Phys self configuring operation at 1.5 and 3.0 Gb/s
Automatic speed detection/negotiation
Larger table routing capability (320 entries)
The most efficient table routing implementation
Other implementations will waste entries for unused expander PHYs
Up to 60 general purpose IO, reduces external components

29. Single JBOD Configuration
Server with SAS HBA
or SAS RAID card
SFF SFF8088
(infiniband) miniSAS
26-pin
For host for JBOD

30. JBOD Cascading Configuration
Server with SAS HBA
or SAS RAID card

31. Fault Tolerance with JBOD Cascading
Server with SAS HBA
or SAS RAID card
Server with SAS HBA
or SAS RAID card

32. Q & A