Storage in csc well explainr=ed

1. CLIENT SERVER COMPUTING –DATA
STORAGE
II ME CSE
2015-16 ODD SEMESTER (III SEMESTER)
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2. Topics
Magnetic Disk
MagneticTape
CD ROM
Worm
Optical Disk
Mirrored Disk
FaultTolerance
RAID
Network Protection Devices
Power Protection Devices
Client Server System Development
Remote System Management
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3. Magnetic Disk
• There are various types of auxiliary storage; all of them involve some type of magnetic
disk.
• It uses magnetism to store the data on a magnetic surface.
• The advantages associated with such type of storage media
– high storage capacity,
– reliable and
– provides direct access to the data.
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4. Magnetic Disk
• The available magnetic disks are
– Diskette –Floppy disk
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5. Magnetic Disk
– Hard Disk
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6. Magnetic Disk
• What happens when a disk is formatted?
– Whether all data is erased?
– Surfaces are checked for physical and magnetic defects.
– A root directory is created to list where things are on the disk.
– The capacity of a magnetic disk depends on several factors.
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7. Magnetic Tape
• Magnetic tape is a secondary storage device, generally used for backup purposes.
• They are permanent and not volatile by nature.
• The speed of access can be quite slow, however, when the tape is long and what you
want is not near the start.
• So this method is used primarily for major backups of large amounts of data.
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8. Magnetic Tape
• The format method will determine
the some important characteristics
like
– Density
– Block
– Gap
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9. CD-ROM
• CD-ROM (Compact Disc, read-only-memory) is an adaptation of the CD that is
designed to store computer data in the form of text and graphics, as well as hi-fi stereo
sound.
• Although the disc media and the drives of the CD and CD-ROM are, in principle, the
same, there is a difference in the way data storage is organized.
• Two new sectors were defined
– CD-ROM Mode 1 for storing computer data.
– CD-ROM Mode 2 for compressed audio or video/graphic data.
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10. CD-ROM
• Data Encoding and Reading
– The CD-ROM, like other CD adaptations, has data encoded in a spiral track beginning
at the center and ending at the outermost edge of the disc.
– The spiral track holds approximately 650 MB of data.That's about 5.5 billion bits.
– The track pitch can range from 1.5 to 1.7 microns, but in most cases is 1.6 microns.
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11. CD-ROM
• Constant LinearVelocity (CLV)
– CLV is the principle by which data is read from a CD-ROM.
– Principle states that the read head must interact with the data track at a constant rate,
whether it is accessing data from the inner or outermost portions of the disc.
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12. WORM
• WORM (write once, read many) is a data storage technology that allows
information to be written to a disc a single time and prevents the drive from
erasing the data.
• The discs are intentionally not rewritable, because they are especially intended to
store data that the user does not want to erase accidentally.
• Used for the archival purposes of organizations such as government agencies or
large enterprises.
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13. WORM
• The discs have varied in size from 5.25 to 14 inches wide, in varying formats
ranging from 140MB to more than 3 GB per side of the (usually) double-sided
medium.
• Data is written to aWORM disc with a low-powered laser that makes permanent
marks on the surface.
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14. WORM
Top: the hybrid organic/inorganic
semiconductorWORM memory
Bottom: Diagram of theWORM
memory element used in this study Also
shown is the chemical structure of the
two-component electrochromic polymer
PEDOT (polyethylenedioxythiophene
(PEDT): polystyrene sulphonic acid
(PSS)
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15. Optical Disk
An optical disc holds much more data.
The greater control and focus possible with laser beams (in comparison to tiny
magnetic heads) means that more data can be written into a smaller space.
An optical disc is an electronic data storage medium that can be written to and
read using a low-powered laser beam.
Storage capacity increases with each new generation of optical media.
Emerging standards, such as Blu-ray, offer up to 27 gigabytes (GB) on a single-
sided 12-centimeter disc.
Optical discs are inexpensive to manufacture.
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16. Variants
Read-Only (Factory Pressed)
•Read-only discs are pressed from a master at the time of manufacture and cannot
be erased.CD-ROM, DVD-ROM, DVD-Video and BD-ROM (Blu-ray).
Write-Once (Burnable)
•Write-once discs are recorded in the user's environment but cannot be erased.
They include the CD-R, DVD-R, DVD+R, BD-R (Blu-ray),WORM discs, as well as
magneto-optic (MO) discs inWORM mode.
Rewritable (Phase Change and Magneto Optic)
•Rewritable discs can be written and re-written numerous times. Employing phase
change technology, consumer-oriented products include CD-RW, DVD-RAM,
DVD-RW, DVD+RW and BD-RE (Blu-ray)
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17. RAID
Redundant Arrays of Independent Disks
Motivation
Typical memory bandwidths ≈ 150 MB/sec
Typical disk bandwidths ≈ 10 MB/sec
Result: I/O-bound applications limited by disk bandwidth
 (not just by disk latency!)
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18. Solution: Exploit Parallelism
Stripe the data across an array of disks
many alternative striping strategies
possible
Example: consider a big file striped
across N disks
stripe width is S bytes
hence each stripe unit is S/N bytes
sequential read of S bytes at a time
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19. Performance Benefit
Sequential read or write of large file
application (or I/O buffer cache)
reads in multiples of S bytes
controller performs parallel access of
N disks
aggregate bandwidth is N times
individual disk bandwidth
(assumes that disk is the bottleneck)
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20. N concurrent small read or write requests
randomly distributed across N drives
(we hope!)
common in database andWeb server
environments
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21. RAID Approaches
Many alternative approaches to achieving this redundancy
RAID levels 1 through 5
hot sparing allows reconstruction concurrently with accesses
Key metrics to evaluate alternatives
wasted space due to redundancy
likelihood of “hot spots” during heavy loads
degradation of performance during repair
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22. RAID Level 1
Also known as “mirroring”
To read a block:
read from either data disk or backup
To write a block:
write both data and backup disks
failure model determines whether writes can
occur in parallel
Backups can be located far way:
safeguard against site failure
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23. RAID Levels 2 & 3
These are bit-interleaved schemes
In Raid Level 2, P contains memory-
style ECC
In Rail Level 3, P contains simple
parity
Rarely used today
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24. RAID 4
Block-interleaved parity
Wasted storage is small: one parity
block for N data blocks
Key problem:
parity disk becomes a hot spot
write access to parity disk on every
write to any block
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25. RAID 5
Rotated parity
Wastage is small: same as in Raid 4
Parity update traffic is distributed
across disks
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26. RAID 5 Actions
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27. Network Protection Device /Security Appliance
 SecurityAppliance or Network Protection is used to control network access of a
computer
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28. Network Protection DevicesNetwork Protection Devices
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• It is designed to protect computer networks from
unwanted traffic
• Examples include
–CyberRoam Security devices, Firewalls ,Secured Routers etc.,
• 4 Types of Network Protection devices
–Active devices
–Passive devices
–Preventative devices
–Unified Threat Management (UTM)

29.  Active devices - block unwanted traffic. Eg: such devices are firewalls, anti virus
scanning devices, and content filtering devices.
 Passive devices - detect and report on unwanted traffic, such as intrusion
detection appliances.
 Preventative devices - scan networks and identify potential security problems (such
as penetration testing and vulnerability assessment appliances).
 UnifiedThreat Management (UTM) appliances combine features together into one
system, such as some firewalls, content filtering, web caching etc.
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30. Eg1: CyberRoam Security Device
• Available as UTMs and Next Generation Firewalls, deliver
enterprise-class network security with stateful inspection firewall,
VPN and IPS.
• This ensures high levels of network security, network connectivity,
continuous availability.
• Offers enterprise-class security and high flexibility with protection
against blended threats, malware, Trojans, DoS, DDoS, IP spoofing
attacks, spam, intrusions and data leakage.
• http://www.cyberoam.com/networksecurity.html
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31. Eg2: Cisco PIX (Private Internet eXchange)
• IP firewall and network address translation (NAT)appliance
• First commercially available firewall product to introduce
protocol specific filtering with the introduction of the
"fixup" command
• PIX "fixup" capability allows the firewall to apply additional
security policies to connections
• Incorporates IPSec VPN gateway functionality
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32. Power Protection Devices and its need?
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• Power protection system - connected to a single power-
protection source, such as an uninterruptible power supply
(UPS).
• First, power-protection equipment must contend with an
increasingly wide range of system configurations.
–Servers, workstations, routers, hubs, bridges and other sensitive
components must all be taken into consideration.
• Second, as computer-based systems become more integral
to telecommunications operations a minor power problem
has catastrophic effects

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• Uninterruptible power source, UPS or battery/flywheel backup -
electrical apparatus that provides emergency power when the input power
source, typically mains power, fails.
• A UPS differs from an auxiliary or emergency power system or standby
generator
• Provides near-instantaneous protection from input power interruptions,
by supplying energy stored in batteries,supercapacitors, or flywheels.
• The on-battery runtime of most uninterruptible power sources is relatively
short but sufficient to start a standby power source or properly shut down
the protected equipment.

34. Power Management (PM)
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• Typically used to protect hardware such as computers, data
centers, telecommunication equipment or other electrical equipment
• Three general categories of modern UPS systems are
–on-line,
–line-interactive and
–Standby
• Power management (PM) requires the UPS to report its status to the
computer it powers via a communications link such as a serial
port, Ethernet and Simple Network Management Protocol,
GSM/GPRS or USB
• A subsystem in the OS that processes the reports and generates
notifications, PM events, or commands an ordered shut down.

35. System Administration
•System administration is the field of work in which
someone manages one or more systems like software,
hardware, servers or workstations.
•Its goal is ensuring the systems are running efficiently and
effectively.
•Duties of a system administrator.
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36. System Administrator's Responsibilities
• Morning checks of systems/software.
• Performing backups of data.
• Applying operating system updates, and configuration changes.
• Installing and configuring new hardware/software.
• Adding/deleting/creating/modifying user account information, resetting passwords, etc.
• Answering technical queries.
• Responsibility for security.
• Responsibility for documenting the configuration of the system.
• Troubleshooting any reported problems.
• System performance tuning.
• Keeping the network up and running.
• Technical support
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37. Reliability, Availability and Serviceability (RAS)
Reliability, Availability and Serviceability (RAS) is a set of related attributes that must be
considered when designing, manufacturing, purchasing or using a computer product or component.
•The term was first used by IBM to define specifications for their mainframe s and originally applied only
to hardware .
•Reliability-> ability of a computer-related hardware or software component to consistently perform
according to its specifications.
•In theory, a reliable product is totally free of technical errors.
•In practice, vendors commonly express product reliability as a percentage.
•Availability ->ratio of time a system or component is functional to the total time it is required or
expected to function.
•Serviceability -> expression of the ease with which a component, device or system can be maintained
and repaired.
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38. Key elements of RAS are:
•Over-engineering, which is designing systems to specifications better than minimum
requirements.
•Duplication, which is extensive use of redundant systems and components.
•Recoverability, which is the use of fault-tolerant engineering methods.
•Automatic updating, which is keeps OSs and applications current without user intervention.
•Data backup , which prevents catastrophic loss of critical information.
•Data archiving , which keeps extensive records of data in case of audits or other recovery needs.
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39. Network Management
• Network management refers to the broad subject of managing
computer networks.

There exists a wide variety of software and hardware products that help
network system administrators manage a network.
•
Network management covers a wide area, including:
–
Security: ensuring that the network is protected from unauthorized
users.
–
Performance: eliminating bottlenecks in the network.
–
Reliability: making sure the network is available to users and
responding to hardware and software malfunctions.
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40. Architecture
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41. NETWORK MANAGEMENT SYSTEM
Network management system (NMS) is a set of hardware or software tools that
allow an IT professional to supervise the individual components of a network
within a larger network management framework.
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42. NMS
Network management system components assist with:

Network device discovery - identifying what devices are present on a
network.

Network device monitoring - monitoring at the device level to determine the
health of network components and the extent to which their performance matches
capacity plans and intra-enterprise service-level agreements (SLAs).
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43. NMS
Network performance analysis - tracking performance indicators such as
bandwidth utilization, packet loss, latency, availability and uptime of routers,
switches and other Simple Network Management Protocol (SNMP) -enabled
devices.
Intelligent notifications - configurable alerts that will respond to specific
network scenarios by paging, emailing, calling or texting a network administrator.
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44. SNMP
Simple Network Management Protocol (SNMP) is the protocol governing
network management and the monitoring of network devices and their functions.
SNMP uses the User Datagram Protocol (UDP) and is not necessarily
limited toTCP/IP networks.
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45. Components
An SNMP-managed network consists of three key components:
Managed device - A managed device or the network element is a part of the
network that requires some form of monitoring and management e.g. routers,
switches, servers, workstations, printers, UPSs, etc...
Agent — software which runs on managed devices.
Network management station (NMS) — software which runs on the
manager.
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46. Principle of SNMP Communication
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47. Remote Systems Management Security
REMOTE ADMINISTRATION:
• Remote administration refers to controlling a computer from a remote location.
• Software that allows remote administration is becoming increasingly common and
is often used when it is difficult or impractical to be physically near a system in
order to use it.
• A remote location may refer to a computer in the next room or one on the other
side of the world.
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48. Security requirements
• Confidentiality
• Integrity
• Authentication
• Non-repudiation
• Availability
• Access control
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49. Security services
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50. What are Remote Management Services?
• Cisco Remote Management Services (RMS) enable us to simplify the adoption
and management of technologies.
• Through maximized high performance and increasedavailability and use of these
solutions, we can realize our return on technology investments faster with
proactive,continuous remote monitoring and management of the network
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51. RMS
• With RMS, we can anticipate, identify and resolve issuesfaster and with greater
accuracy while retaining as much visibility and control as our desire.
• Our renowned support comes from certified Cisco experts with extensive
experience across a broad spectrum of technologies combined with a wealth of
best practices, Cisco intellectual capital, smart capabilities and service
automation that truly differentiate the customer experience.
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52. Remote Management Services Overview
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53. RMS ValuePeople, Tools and Processes
• Utilizing ITIL methodologies and Cisco best practices to fully utilize the depth
of our global user experiences to trend, analyze and quickly resolve issues faster.
• This increases the value of our investment by improving the user experience with
clearly defined processes.
• The power of our industry leading standards, tools and automation specifically
address your support challenges, effectively reaching resolution faster and
consistently managing complex enterprise environments
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54. RMS ValuePeople, Tools and Processes
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55. NETWORK MANAGEMENT ISSUES
• Failure to properly configure firewalls
– In a good network design, an enterprise should protect its systems with both
network and host firewalls.
– Failing to properly configure firewalls creates a foothold for the exploitation of
other vulnerabilities.
• Failure to authenticate network users.
– It's a good idea to use some form of authentication technology, such as 802.1x, to
ensure that devices connecting to your network are associated with an authorized
user.
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56. • Use of weak (or no) wireless encryption.
– Believe it or not, many enterprises still useWEP encryption to "protect" their networks.
– WEP encryption is fundamentally flawed and should never be relied upon to secure a
wireless network. UseWPA encryption instead.
• Failure to patch.
– Everyone knows that it's important to apply vendor security patches to systems and
applications.
– In fact, a recent study showed that many Oracle administrators have never applied patches
to their systems.
– This is a bad idea, as hackers keep a close eye on security bulletins, looking for exploitable
flaws.
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