Class 3 Agenda

1
Class 3 Agenda

• Review
• Data Management
• State St Bank Case
• Text Network Effect

2
Review

• Network Concepts Take-aways
• IP Address Shortage

3
Data Management Concepts

• Representing Data
• Character Sets
• Binary formats
• Structured/Non-structured data
• File Systems
• Storage Arrays and RAID
• Server Mass Storage Mechanisms
• Storage Area Networks
• Network Attached Storage

4
Character Sets

• Representations of all text elements
• ASCII Standard for PCs, unix
• EBCDIC The Mainframe alternative
• UNICODE The web standard many more characters

5
Ascii Character Set Example(with Parity)
0 0 1 1 0 1 0 1 5
0 1 0 0 0 0 0 1 A
1 1 1 0 0 0 0 1 a
_ _ _ _ _ _ _ _
6
Structured vs Non-structured Files

• Definition
• Impact on Storage
• Impact on Access
• Self-defining records

7
File System Concepts and Issues

• Storage Blocks and Sectors
• Writing and caching
• Fragmentation and re-organization
• Organization File Hierarchies
• Folders, directories and qualifiers
• Inheriting and overriding properties
• Shared File Systems
• Client Sharing
• File Servers

8
Shared Storage Arrays

• Level of abstraction / Virtualization
• Vendors StorTek, IBM, EMC, HP,
• Goals Management, flexibility
• Issues Connectivity, Security

9
Non-Storage Array Model
disk1
svrA
disk2
svrB
disk3
svrC
10
Storage Array Model
D I S K A
disk1
svrA
disk2
svrB
disk3
svrC
11
RAID (redundant array of independent disks)

• RAID 0 (Striping)
• Consecutive blocks written to different disks
• Performance gain only
• RAID 1 (Mirroring)
• Writes all data to two separate drives
• Reads from either for performance
• RAID 5 (Parity disk)
• Any disk can fail without loss
• Parity drive allows failed drive to be recreated

12
RAID 0 Diagram(Striping)
Disk A
Disk B
Disk C
Disk D

Block 4
Block 1
Block 2
Block 3
13
RAID 1 Diagram(Mirroring)
Disk A
Disk B
Block 1

14
RAID 5 Diagram(with even Parity)
Disk A
Disk B
Disk C
Disk D
Parity Disk
0 1 0 1
0 1 1 1 0
1 1 1 0 0
0 0 1 0
0 1
15
Advanced Data Management

• SYSTEM Managed Storage
• Multiple levels of access
• Automatic promotion/demotion
• Catalog of where
• Merging of backup copies
• Master Data Management
• On Common functions tier shared by business
  applications
• Mechanism for sharing, requesting changes
• Resolves duplicates, ownership, domains

16
Storage Area Networks

• Fabric connectivity between servers and storage
• Access is still via owning server
• Used for structured data, data associated with
  specific application
• Typically use specialized connections

17
Fabric Storage Area Network
Disk A
Disk B
Disk C
Disk D
Disk E
SAN Side 1 SAN Side 2
Server 1
Server 2
Server 3
Server 4
18
Network-Attached Storage

• File systems accessed via internet
• Appear as remote drives
• Used for unstructured data (e.g. documents), data
  used by many servers

19
NAS Diagram
NAS
Network
Server
Server
20
State St. Bank A Higher Power

• Distinguish Governance from Management
• Governance is necessary in every aspect of
  business. Why is it singled out in IT/IS
  management?
• Why not take over and run the Deutsche Bank
  applications as is?
• What information is needed for proper decisions
  on a client? Who is responsible for that
  information?
• What type of planning and preparation enhance
  nimbleness?

21
Homework

• Mon Text Chapter 4 Moores Law
• Wed Case Study Netflix (Chapter 3 in
  Gallaugher)
• Wed Receive take home midterm exam (due next
  Monday)