Transcript IBM Jupiter

DAS, NAS and SAN
Ryan Leonard
Storage and Solutions Architect
Statements of IBM future plans and directions are provided for information purposes only.
Plans and direction are subject to change without notice.
© 2009 IBM Corporation
System Storage
July 2009
Agenda
 DAS, NAS, and SAN
 SAN host interfaces
– SAS
– iSCSI
– FC
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
3 categories of external storage
 DAS
– Direct-attached storage device
– Generally attached / dedicated to a
specific server
 NAS
– Network-attached storage
– Connected to a server via a network
– Can be shared or dedicated
 SAN
– Storage Area Network
– Connected to server via a storage
network
– Can be shared or dedicated
Server A
Server B
Server C
Ethernet
JBOD A
JBOD B
JBOD C
Server A
Server B
Server C
Ethernet
NAS
Server A
Server B
Server C
Ethernet
SAN
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
Why use either a SAN or NAS?
 Why consolidate anything?
– Let’s consider an analogy
 Greater efficiency
 Simplified management
 Increased utilization
 Reduced cost
 Leverage features
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
NAS detail
 NAS
– Provides file-level access to storage
• Ethernet connectivity / TCP/IP
• CIFS (Common Internet File System)
• NFS (Network File System)
– Networked file system allows for concurrent access to data
– Several layers between data request and receipt
Server
NAS
NFS/CIFS
TCP/IP
Data
Storage controller
Disk(s)
NIC
HBA
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
SAN detail
 SAN
– Provides block-level access to storage
• Ethernet (iSCSI)
• Fibre Channel
– Concurrent access generally not allowed to specific datasets
– Remote disk(s) appear as locally attached block devices to server
Server
Storage controller
Disk(s)
Data
HBA
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
Interface Options
 Serial attached SCSI (SAS)
 iSCSI
 Fibre Channel (FC)
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
SAS Basics and Benefits
 SAS – Serial Attached SCSI
– A serial communication protocol designed for transfer of SCSI
commands and data to and from devices over point-to-point
interconnections
 Key Benefits
– New roadmap with industry-wide acceptance
– Significant performance enhancements
• 3-Gbps SAS x4 “wide” ports
– Cost equivalent to parallel SCSI
– Freedom from 15 drive maximum per SCSI channel
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
SAS Special Considerations
 Distance limitations – 8 meters per discreet connection
 Perceived complexity based on the newness of the technology
 SAS expanders, which will support SAN-like capabilities for SAS,
are still in development
 Limited to the number of servers that can be attached – based on
the number of SAS host ports on the storage system
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
SAS Positioning
 Excellent solution for directly attaching one to three local servers
to a single storage device
– Cost-effectively facilitates one-room storage configurations
– Offers outstanding performance
– No networking expertise necessary – removes complexity
– Low cost and simple to use
– High bandwidth and low latency
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
iSCSI Basics and Benefits
 iSCSI - internet Small Computer System Interface
– A network protocol that enables transmission of SCSI commands
and data over an IP-based network usually via an Ethernet interface
 Key Benefits:
– Low cost
– Less complexity
• Extensive knowledge base – expertise in every IT organization
– Flexible configuration topologies
– Extensive reach with no distance limitations
– Future performance
• 1Gb/s today with roadmap for 10Gb/s and beyond
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
iSCSI Special Considerations
 Network congestion risks the dropping of frames – important
to evaluate configuration to foresee any bottlenecks
 Achievable performance is misunderstood
– Hardware and connection parameters can be leveraged to achieve
desired performance
 Security at risk when sharing IP storage networks with the
existing network
– Separate storage traffic from normal LAN traffic
 Disparate expertise and confusion over storage and networking
IT roles
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
iSCSI Positioning
 Interface of choice for entry-level and SMB storage networks
where FC is cost prohibitive
– iSCSI has turned the corner, with a large number of installations in
companies of all sizes
– Users are growing more familiar with the lower-cost alternative to FC
– Reach – IP SANs can to be located virtually anywhere.
– Minimal storage investment – utilize existing IP SAN and additional
equipment is relatively inexpensive
– Leverage existing IT resources – in-house IP expertise
– Simplify installation and management – a mature technology with
proven management tools can be easily facilitated
– Extend shared storage benefits to all servers – with minimal
per-server connectivity costs
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
FC Basics and Benefits
 FC – Fibre Channel
– A serial networking interface that supports the transmission of upper
level protocols – including SCSI command sets and data – over fiber
optic or copper cables
 Key Benefits
– Scalable – supports up to 16 million addresses.
– Distance – 10,000 meters maximum cabling length
– High bandwidth – low latency and high IOPs
– Investment protection – auto-negotiating link speeds allowing for
seamless integration into an existing 1Gb/s or 2 Gb/s environment
– Congestion free with credit-based flow control delivering data as fast
as the destination buffer is able to receive it.
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
FC Special Considerations
 Steep learning curve for administrators unfamiliar with deployment
and management
 Expensive and complex
– Costly FC SAN equipment and maintenance
– Training personnel internally or hiring a service company is a
significant addition to TCO
 Low-cost servers will typically not be included as the investment
to attach it can outweigh the cost of the server itself – does not
always make financial sense to deploy
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
FC Positioning
 Dominates SANs today and expected to retain dominance in the
enterprise market
– FC will maintain advantages in both performance and scalability
– Most mature and time-proven designs
– High addressability necessary for large customers with thousands of
servers
– Takes the fullest advantage of server clusters
• 4, 8, 16 and up to 100 or more servers as needed
– Data integrity – class of service settings guarantees delivery of
frames
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
To simplify…
 Pick 2…
Performance
FC
SAS
Scalability
Cost
iSCSI
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.
System Storage
July 2009
Summary
 DAS, NAS, and SAN have intrinsic differences
– Cost
– Performance
– Ease of management
 SAS, iSCSI, and FC
– Cost vs. scalability vs. performance
Statements of IBM future plans and directions are provided for information
purposes only. Plans and direction are subject to change without notice.