Transcript 1 1 1 0 0 0 0 1 = a 0 1 0 0 0 0 0 1 = A 0 0 1 1 0 1 0 1 = 5

Class 3 Agenda
 Review
 Data Management
 State St Bank Case
 Text: Network Effect
Review
 Network Concepts Take-aways
 IP Address Shortage
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
Character Sets




Representations of all text elements
ASCII – Standard for PC’s, unix
EBCDIC – The Mainframe alternative
UNICODE – The web standard:
many more characters
Ascii Character Set Example
(with Parity)
0 0 1 1
0 1 0 0
0 1 0 1 = 5
0 0 0 1 = A
1_ 1_ 1_ 0_
0_ 0_ 0_ 1_ = a
Structured vs Non-structured
Files




Definition
Impact on Storage
Impact on Access
Self-defining records
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
Shared Storage Arrays
 Level of abstraction / Virtualization
 Vendors: StorTek, IBM, EMC, HP, …
 Goals: Management, flexibility
 Issues: Connectivity, Security
Non-Storage Array Model
svrA
disk1
svrB
disk2
svrC
disk3
Storage Array Model
svrA
disk1
D
I
svrB
disk2
S
svrC
disk3
K
A
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
RAID 0 Diagram
(Striping)
Disk
A
Disk
B
Disk
C
Disk
D
Block
1
Block
2
Block
3
Block
4
RAID 1 Diagram
(Mirroring)
Disk
B
Disk
A
Block
1
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
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
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
“Fabric” Storage Area
Network
Disk
A
Disk
B
SAN Side 1
Server 1 Server 2
Disk
C
Disk
D
Disk
E
SAN Side 2
Server 3
Server 4
Network-Attached Storage
 File systems accessed via internet
 Appear as remote drives
 Used for unstructured data (e.g.
documents), data used by many
servers
NAS Diagram
NAS
Network
Server
Server
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”?
Homework
 Mon: Text Chapter 4: Moore’s Law
 Wed: Case Study: Netflix (Chapter 3
in Gallaugher)
 Wed: Receive take home midterm
exam (due next Monday)