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Chapter 14:
System Administration
Mark Milan
System Administration
• Acquiring new IS resources
• Maintaining existing IS resources
• Designing and implementing an IS
security policy
Strategic Planning
• Strategic plan – a set of long-range goals and a plan to attain
those goals.
• The goals must include:
– Services to be provided
– Resources needed to provide those services
• The plan to address the goals are:
– Strategies for developing services and a market for them.
– Strategies for acquiring sufficient resources for operations
and growth.
– Organizational structure and control.
Hardware and Software as Infrastructure
Capital resources are referred to as infrastructure
and have the following characteristics:
– Service to a large and diverse set of users.
– Costs that are difficult t allocate to individual
users.
– Recurring need for new capital expenditures.
– Significant operating costs for maintenance.
Standards
• Providing infrastructure-based services to a wide
variety of user requires adopting services standards.
• Standardization causes problems for users that
want services near the leading edge.
• It is hard to standardize when dealing with hardware
and software.
Competitive Advantage
• Competitive Advantage describes a state of affairs in which
one organization employs resources so as to give it a
significant advantage over its competitors.
The different forms includes:
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Providing services that competitors are unable to provide.
Providing services of unusually high quality.
Providing services at unusually low price.
Generating services at unusually low cost.
Acquisition Process
• Determining and Stating
Requirements
• Request for Proposals
• Evaluating Proposals
Acquisition Process
The acquisition process consists of the following process:
1. Determine the applications that the
hardware/software will support.
2. Specify detailed requirements in terms of hardware
and software capability and capacity.
3. Draft a request for proposals and circulate it to
potential vendors.
4. Evaluate the responses to the request for
proposals.
5. Contract with a vendor or vendors for purchase,
installation, and/or maintenance.
Determining Requirements and
Evaluating Performance
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Modeling Concepts
Computer System Models
Application Demand Models
Resource Availability Models
Model Manipulation and Analysis
Measuring Resource Demand and
Utilization
Determining H/W Requirements
and Evaluating Performance
Determining hardware requirements for a
specific set of application software is difficult:
• Computer systems are complex combinations of
interdependent components.
• The configuration of operating and other system
software can significantly affect raw hardware
performance.
• The hardware and system software resources
required by applications cannot always be predicted
precisely.
Measuring and Utilizing
Automated tools to measure resource
demand and utilization include:
– Hardware monitors
– Software monitors
– Program profilers
Security
Security system measures:
• Protect physical resources against accidental loss or
damage.
• Protect data and software resources against
accidental loss or damage.
• Protect all resources against malicious tampering.
• Protect sensitive software and data resources
against unauthorized access and accidental
disclosure.
Security
Access Controls - specific access controls can
include restrictions on:
• Locations from which a user can log on to the
system or access its resources.
• Days/times when access is granted or denied.
• The ability to read, write, create and delete
directories and files.
• The ability to execute programs.
• The ability to access hardware resources such as
printers and communication devices
Security
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Methods to enhance Password Controls and
Security:
Restrictions on the length and composition of valid
passwords.
Requirements that passwords periodically be
changed.
Analysis of password content to identify passwords
that are guessed easily.
Encryption of passwords in files and during
transmission over a network.
Restrictions on locations from which a user can
access the system.
Physical Environment
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Electrical Power
Heat Dissipation
Moisture
Cable Routing
Fire Protection
Electric Power
Fluctuations in power can cause:
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Momentary power surges
Momentary power sags
Long-term voltage sags
Total loss of power
Heat Dissipation
• All computer equipment requires some
means of heat dissipation.
• Many hardware devices use fans to
move air through the unit.
• Auxiliary cooling can be provided within
an individual equipment cabinet.
Moisture
• Excessive moisture is an enemy of electrical
circuitry.
• Well-designed cabinets are one defense
against the dangers of moisture.
• Humidity can be controlled automatically by
optional components of heating, ventilation
and air conditioning systems.
Cable Routing
• A raised floor is generally used in a room
that contains multiple hardware cabinets, a
single mainframe computer system or
multiple minicomputers.
Fire Protection
• Carbon dioxide, fire retardant foams and powders,
and various gaseous compounds are alternate
methods of fire protection, but not for computer
equipment.
• Halon gas is used around computer equipment
since is does not promote condensation.
Disaster Planning and
Recovery Measures
• Periodic data backup and storage of backups at
alternate sites.
• Backup and storage of critical software at alternate
sites.
• Installing of duplicate or supplementary equipment
at alternate sites.
• Arrangements for leasing existing equipment at
alternate sites, such as with another company or a
service bureau.