ML280 iSCSI Architecture and Instrumentation
BASIC ELEMENTS OF iSCSI
This section identifies the basic features of and the premises upon which iSCSI products have been designed to date. iSCSI is discussed in terms of the OSI model of computer networking. Upon completion students are able to:
- Define iSCSI.
- Identify the basic features of iSCSI.
- Describe how iSCSI may be used to complement existing storage technologies.
iSCSI ARCHITECTURAL AND THE NETWORK
This section discusses the logical architectural design of iSCSI. iSCSI-specific objects and terminology are identified.Upon completion students are able to:
- Identify iSCSI's place in the network stack.
- Identify when a new TCP connectionis being created.
- Describe how iSCSI provides for network security using IPSec.
- Define an iSCSI Connection, including its relationship to the TCP connection.
- Define an iSCSI Session and its relationship to an iSCSI connection.
- Define an iSCSI Portal Group and identify how it is used.
- Describe the iSCSI Acknowledgement model.
iSCSI COMMUNICATION: PROTOCOL DATA UNITS
This section introduces the iSCSI Protocol Data Unit (PDU) format and usage. iSCSI transmission inside of the TCP/IP stack is discussed and illustrated. Upon completion students are able to:
- Identify the fields of a general iSCSI PDU.
- Identify the possible headers in an iSCSI PDU and when each is used.
- Describe how segmentation by other network layers affects iSCSI transmission.
NAMING, ADDRESSING AND DISCOVERY
This section covers the requirements for naming and addressing iSCSI components.Multiple options for the discovery of iSCSI objects are discussed.iSCSI traces are used to illustrate the iSCSI discovery process. iSCSI Security requirements are also discussed. Upon completion students are able to:
- Differentiate between the 3 iSCSI Discovery processes.
- Identify 2 possible protocols for discovery management on large networks.
- Describe the iSNS registration and query processes.
CONFIGURING TARGETS
This section covers the Normal Login process in iSCSI.Students study several login traces representing the login processes of a variety of iSCSI vendors. Upon completion students are able to:
- Define how the iSCSI Login relates to the iSCSI Session.
- Explain the 2 stages of the Login process.
- List the components which may be negotiated during Security Negotiation.
- List multiple components which may be negotiated during Operational Negotiaiton.
- Define how the CHAP security process is carried out within an iSCSI Login.
MAPPING SCSI INTO iSCSI
This section covers the actual mapping of SCSI commands, data and status into iSCSI PDUs. Trace analysis covers various SCSI commands (e.g. Read, Write, Inquiry, Test Unit Ready) carried on the iSCSI transport layer. Upon completion students are able to:
- Identify the flow of an iSCSI transmission.
- Explain under what circumstances the SCSI Status phase may be collapsed into the Data Phase in iSCSI, including how this affects the layout of the PDU.
- Identify how targets use R2T PDUs to flow control SCSI Write operations.
iSCSI ERROR DETECTION AND RECOVERY
This section discusses the error recovery hierarchy as outlined in the iSCSI draft specification. Students analyze controlled traces for errors and recovery processes ranging from failed login negotiation to SCSI Check Conditions. Upon completion students are able to:
- Identify how digest errors affect iSCSI transmission flow.
- Identify how iSCSI recovers from errors that are within-command and within-connection.
- Describe how iSCSI detects and recovers from connection failure.
- Describe the effects of iSCSI Session Recovery.
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