1) What is the difference between UNIX and windows
operating systems?
Ans. UNIX supports
multithreading where as windows does not support multithreading. UNIX is an operating system which supports multithreading.
The question u
got is what is an threading - threading is nothing but like a process but it is
more faster than a process.
The threads are
more efficient than the process because it share memory instead of system call.
Here u may get a
doubt that what is a system call.
A system call is
invoked as a mediator between a process and operating system.
Threading flows
in a sequential process.
In threading we
have single threading and multiple threading.
The best example
i can give u is as we know that in UNIX many users share memory but they may
not know that they are sharing.
Here if a user
have multi threading (that is he is using the Unix)he need to complete a task
i.e. a spread sheet consist of different calculations.
if one row is
changed entire complete spread sheet should be changed.
So here for
every task one thread is allotted so the task is completed more faster than a
system call.
2) Describe four general strategies for dealing with deadlock.
Ans. the four techniques are- 1) mutual exclusion. 2) Circular wait. 3)
Hold & wait
4) no preemption
4) no preemption
3)
OS Beep
Sounds.
Ans. single beep stands for error in Refreshing
Double Beep stands for error in memory
Continuous beep sound tells stands for RAM not working or RAM properly not inserted in slot
Double Beep stands for error in memory
Continuous beep sound tells stands for RAM not working or RAM properly not inserted in slot
4) What is the structure of file system? At the time
when we create a partition how the blocks are allocated.
Ans. At the time of buying the hard-disk you will have
full 80 GB. but after you format it, you will see that the size is reduced to
78 GB or so. That is bcoz the entire hard disk is divided in to several sectors
and each sector is classified as "Data section" and "Address
section". This address section constitutes some bytes and hence al
together you may lose some 1 or 2GB.
The OS or the file systems of OS are responsible for these address translations.
The device driver translates the  block address to physical address [track, sector etc.,]
Thus the file system would set up several tables for denoting the free sectors, for denoting the sectors for a particular user etc.
The OS or the file systems of OS are responsible for these address translations.
The device driver translates the  block address to physical address [track, sector etc.,]
Thus the file system would set up several tables for denoting the free sectors, for denoting the sectors for a particular user etc.
5) What is the difference between multi programming
operating system and multiprocessing operating system?
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Ans. A multi processing os supports multiple processes to run with the help
of some scheduling algorithm(round robin) its mean u can run multiple process
at same time, there are two type of multi processing os 1) multiprocessing :-
single Processor and multiple process2) symmetric multiprocessing :- multiple
Processor and single processor a multiprogramming OS supports all features
like 1) Multi tasking 2) Multi processing3} Multi threading( thread can also
be considered as a task)but if any of these feature is not supported by the
os then that os cant be multiprogramming os.
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6)
Execution of
program? Can we execute a program with out installing Operating system? If yes,
how it can be done?
Ans. Yes. using EPROM.
7) If the OS is just a collection pf programs and if
it is executed by the processor just like any other program, is the OS a
process? If so, how is it controlled?
Ans. Execution contexts can be of two types:
thread/process context OR an Interrupt context. What this means is that to
execute code, one has to be in a thread context or a an Interrupt context. OS
code or any code for that matter has no context. It is the execution stream
that has a context. So, whenever we are executing OS code, we are doing so on
behalf of one of the two contexts mentioned above.
The behavior of the OS is controlled by user requests via system calls, by interrupt requests and by the policy and mechanisms put in place to manage resources, provide protection, etc.
The behavior of the OS is controlled by user requests via system calls, by interrupt requests and by the policy and mechanisms put in place to manage resources, provide protection, etc.
8) Explain the Windows XP, 2000 and 2003 Boot Process?
Ans. following are the booting
files for xpboot.ini, ntldt, ntdetect.com, ntoskrnl.exe, bootdd.sys, bootsect.dos,hal.dll, system.
First there will be pre- boot sequence, it includes the following
1.POST(power on self test) first check for hardware
2.loads boot.ini, loads mbr.
3.mbr loads active partation
4ntldr loads o.s.
boot process: first loads boot.ini, ntldr will be in boot.ini it loads os. boot.ini shows available os for selection, ntdetect.com check for hardware, ntoskrnl.exe loads drivers for devices.
9) What is DHCP, How it Works?
Ans. DHCP stands for dynamic host
configuration protocol. What it does is dynamically assign
network settings from a server. Hence a DHCP configured PC boots; it requests
its IP address from the DHCP server. It does this by sending a standardized
DHCP broadcast request packet to the DHCP server with a source IP address of
255.255.255.255. If your DHCP server has more than one interface, you have to
add a route for this 255.255.255.255 address so that it knows the interface on
which to send the reply; if not, it sends it to the default gateway. (In both
of the next two examples, we assume that DHCP requests will be coming in on
interface eth0).
10) What do you mean by fault tolerance?
Ans. Fault tolerance is a concept in kernel. There are basically
two types of kernel
[1] Monolithic kernel [used in
windows XP or generally]
[2] Microkernel [used in robotics]
Monolithic kernel has hierarchical
protection domain. That means its hardware management is in ring form. In
monolithic kernel there is single memory and all applications are using same
memory with frequent & good access
of system resources. There resources are linked with h/w. So even a single
fault to hardware can corrupt the whole system.
So in safety of this micro kernel
designed so that even single faults of h/w do not corrupt whole system.
11) Difference between NTFS and FAT32?
Ans. NTFS
1) Allows access local to w2k, w2k3, XP, win NT4 with SP4 & later
may get access for some file.
2) Maximum size of partition is 2 Terabytes & more.
3) Maximum File size is up to 16TB.
4) File & folder Encryption is possible only in NTFS.
FAT 32
1) Fat 32 Allows access to win 95, 98, win millenium, win2k, xp on local
partition.
2) Maximum size of partition is up to 2 TB.
3) Maximum File size is up to 4 GB.
4) File & folder Encryption is not possible.
FAT (FAT16 and FAT32) and NTFS are two methods
for storing data on a hard drive. The hard drive has to either be formatted
using one or the other, or can be converted from one to the other (usually FAT
to NTFS) using a system tool.
NTFS is a high-performance and self-healing file
system proprietary to Windows XP 2000 NT, which supports file-level security,
compression and auditing. It also supports large volumes and powerful storage
solution such as RAID.
The most important new feature of NTFS is the ability to encrypt files
and folders to protect your sensitive data
12) What will happen if you have a set of interrupt
signals arrived at the same time?
Ans. There are some scheduling algorithms to
control the multiple interrupts so many os mostly used priority
based algorithm in this each process allotted with their priorities in that
time they will execute.
If not used any algorithms tat may lead to deadlock state.
If not used any algorithms tat may lead to deadlock state.
13) What is virtual machine?
Ans- A self-contained operating environment that behaves
as if it is a separate computer.
14) Difference between a process and a program ?
Ans. Please do not confuse process with program. Program is only a set of
instructions and process is a program in memory. Thread is a basic unit of
execution within a process. This means program is something which is not
loaded in memory yet. And Process is loaded in memory but not a complete
execution unit. We say only a thread is under execution. I would request some
of my friends, please refer somewhere thoroughly before sending misleading
answers.
15) Discuss the advantages and disadvantages of
removing operating system altogether?
Ans. Advantages
We can use hardware more efficiently, we get efficient results.
Disadvantages
Memory loss, dead locks, pre-emptions, so on...
We can use hardware more efficiently, we get efficient results.
Disadvantages
Memory loss, dead locks, pre-emptions, so on...
16) Can we do thread scheduling? If yes, How do we use?
How to know the priority of thread?
How to know the priority of thread?
Ans. If it is
about scheduling processes nice value comes into picture but when you are
talking about threads (LWP) nice value cannot be used. There are APIs to set
the thread priorities A to affect scheduling.
17) What is the difference between THREAD, PROCESS and
TASK?
Ans. Thread: Thread is separate path of execution which R functionally
independent of each other.
Process: A program in execution is called process.
Task: In program contains tasks. Each task is nothing but job.
Process: A program in execution is called process.
Task: In program contains tasks. Each task is nothing but job.
18) What is the difference between the socket and pipe?
Ans. socket and Pipe are all together different
thinks
Socket -It is part of OSI LAYER MODEL. in
Osi model communication between different layer takes places through sockets.
say application layer provide services trough certain sockets to
presentation layer and presentation layer uses certain other socket to
communicate with upper application layer.
Socket are used in SECURE SOCKET LAYER NETWORKS
Pipes- it is related to processing
of a process in
cpu , pipes are segments of a process in execution.
generally process are divided into distinct segments which are linearly
dependent i. e output of first segment become input for next segment and so on
generally by processing multiple pipes simultaneously ,we can improve
productivity i. e we can run different pipe segment simultaneously, by keeping
in mind ,that they don’t indulge in waiting for each other.
19) What is the difference between safe mode and normal
mode. Difference between 32 bit and 64 bit operating systems?
Ans. In normal mode all drivers are accessed and given access. Where as in
Safe mode only selected drivers are accessed.
A bit is binary
information. It is either 0 (off) or 1 (on). A 64-bit operating system can move
64 bits of data per clock cycle (1 GHz+ moves billions per second). Going from
a 16-bit OS (Windows 3.1) to 32-bit (Windows XP) will make a huge difference on
the same machine.
A 64-bit OS is
better than 32-bit because:
- It effectively doubles system capabilities if the system is running a 64-bit processor.
- More information can be sent at one time on a 64-bit system than on a 32-bit system. It's great for data-intensive programs.
- You can run a 32-bit app on a 64-bit operating system, much like you can run a 16-bit app on Windows XP.
- Microsoft is enabling developers to build 64-bit functionality within its 32-bit programs.
- It effectively doubles system capabilities if the system is running a 64-bit processor.
- More information can be sent at one time on a 64-bit system than on a 32-bit system. It's great for data-intensive programs.
- You can run a 32-bit app on a 64-bit operating system, much like you can run a 16-bit app on Windows XP.
- Microsoft is enabling developers to build 64-bit functionality within its 32-bit programs.
20) What is exchange server?
Ans. Exchange server is a Microsoft product, it is used for mail server with
Microsoft server, it uses AD, Users and other server facility.
21Can we
load Linux OS in micro controller/ ARM processor? if yes then HOW?
Ans. No.
22. Give tabular difference between batch processing,
time sharing, online time sharing, and multiprogramming batch system and
distributed operating systems?
Ans. Batch Processing:In batch processing Operating
systems the tasks are performed in batches,os waits for a batch of tasks to
arrive and performs the operation on the batch.
Time Sharing: in time sharing operating systems the operating systems shares the time between the tasks, i.e. if job A takes 6 minutes to complete and the predefined time to the os is 2 min it first performs the first job A for 2 minutes, then takes up job B(the next one) and this way shares its time between all the jobs arriving.
Online Timesharing: online time sharing operating system has the same function of the time sharing operating system except that the jobs are given time in the order they come.
Multi programming: In multiprogramming batch operating systems the multiplle jobs are performed by the operating system simultaneously at a time.
Distributed Operating systems: in distributed operating systems, different processors that are loosely coupled operate on different jobs and communicate with each other.
Time Sharing: in time sharing operating systems the operating systems shares the time between the tasks, i.e. if job A takes 6 minutes to complete and the predefined time to the os is 2 min it first performs the first job A for 2 minutes, then takes up job B(the next one) and this way shares its time between all the jobs arriving.
Online Timesharing: online time sharing operating system has the same function of the time sharing operating system except that the jobs are given time in the order they come.
Multi programming: In multiprogramming batch operating systems the multiplle jobs are performed by the operating system simultaneously at a time.
Distributed Operating systems: in distributed operating systems, different processors that are loosely coupled operate on different jobs and communicate with each other.
23. What are the Different types of backup?
Ans. When you backup files, means that you make a
safe copy of the file. So when the original data is corrupted , and if there is
a backup of that original data, we can retrieve that original information.Kool
right, so therz no loss of data. Thats why its been used in almost all the
organizations.
Backup devices are:
Floppy drives, LS-120 drives, ZIP drives & Jaz drives.
Incremental—Backs up the files that changed since the
last backup, and marks the files as backed up.
Differential—Backs up the files that changed since the
last backup, but doesn’t mark the files as backed up.
Copy—Backs up the files you select, but doesn’t
mark the files as backed up.
Daily—Backs up the files that changed that day,
but doesn’t mark the files as backed up.
24.
What is the shortest
definition of os?
Ans. OS is a Interface between a user and the
hardware of a computer.
25. Why paging? What is virtual memory? what is virtual address space?
Ans. Paging is a memory management technique used
by operating system.
in it complete memory is divided into logical blocks of equal size.
whenever any page is required o/s search for that page in memory, if it don’t
find than a trap is generated known as Page fault and this new page get loaded
in RAM from secondary memory.
virtual memory is also memory management technique generally deployed
when
a computer is not having enough(large)RAM for a large program to be kept
in memory, but as we know for fast and successful execution of program ,it is
required to be present in memory and our problem is of less RAM
thus virtual memory provide solution to this problem
virtual memory provides mapping technique for Mapping program generated
RAM address to actual physical address of secondary Memory, at run time .it
proved illusion as if our RAM is large enough to hold complete program.
it is generally used in graphic oriented programs and
applications.
26. What is special in SP2 for windows xp?
Ans. With Windows XP Service Pack 2 (SP2), Microsoft is introducing a set of
security technologies that will help improve Windows XP-based computers'
ability to withstand malicious attacks from viruses and worms. These
technologies include:Network protection ,Memory protection, Improved email security, Safer browsing.
ICF internet connection firewall, Enhanced HCL support, Improved wireless support, Bluetooth enabled, Windows media player 9, Internet explorer popup blocker, firewall protection from startup to shutdown.
27. Difference between win98 and windows XP?
Ans. Win98
1. Win98 Support FAT file system & XP support NTFS and Also
FAT.
2. Win98 Does not having Remote Access facility While in XP there is.
3. Win98 Does not need faster processing speed while XP Need 500MHz
processing Speed.
4. Win98 Does not provide System Restore while XP Provide.
5. Win98 does not having Hibernate facility While XP having Hibernate
Facility.
6. Win98 and WinXp layout and visual Styles are Different.
7. WinXp improves Device Support.
8. WinXp having CD Burning Facility, fast user Switching.
9. Ability to support multithreading to utilize hyper threading feature.
28.
Difference between Pentium 3 and Pentium 4?
Ans. The processor frequency up to 1.2 GHz 12.10X
is P3
The processor frequency greater than 1.2 GHz is P4
The Cache memory in P4 is increased compared to P3
In P4 We have a special range of processor with HT technology and Dual
core.
29. What would system restore do? Technically what would it do?
Ans. Its is a kind backup utility, which help when
the O/s gets corrupted or we lose our setting of O/s
Always this should be enabled in windows so that we can restore the
latest settings when we face any problems
30.
Difference between time sharing and multitasking systems?
Ans. Time Sharing: programs are executed in an
interleaved manner that is 1st the programs are merged together to form a
single stream of instruction then given to the processes for execution.Multitasking: programs are kept separate and cpu switches in between the different processes and execute there instruction separately. no interleaving concept is there.
31. In
single networking which addressing is used to send data ? logical or physical
addressing?
Ans. logical address which is used is 127.0.0.1. This is a loop back address.
If you send some data to this address then it comes back to you.
32. What
is Hyper Threading? Tell me about Windows Vista ?
Ans. Hyper threading is Intel’s version of a Multithreading. It duplicates
the front end of the processor Core attempting to schedule / Guess where it can
put threads to better utilize a semi idle processor. The Intel Implementation
was heavily flawed and suffered from Bad branch prediction. On most server
implementations it is advisable to turn Hyper threading off. Also in processor intensive
games, Battlefield 2 ... Hyper threading causes frame lag. If you turn Hyper
threading off you get better FPS.
33. What
is the meaning of physical memory and virtual memory?
Ans. Physical memory is the amount of random
access memory (RAM) in your computer.
Virtual memory is hard disk space reserved to emulate physical memory.
Virtual memory is also called swap space.
34. What
is the difference between general purpose operating system and Real time
operating system?
35. What
is the Hibernation Mode?
Ans. Hibernation mode is used to conserve batteries or power.
When you turn computer into this mode all the application in the memory are
saved on hard disk and computer shuts down. On switching on it resumes where it
left out and this resume operation is quicker than switching on from normal
shut down.
36.
Distinguish between the operation of single and multi user operating systems?
Ans. operation of multi user operating systems are
having the functions like time sharing and data sharing while this is not done
in single user operating system.
37. What
do you understand by MOM?
Ans. MOM stands for
Microsoft Operations Manager. It is an application used for monitoring health
of servers. MOM can monitor lot of things in a server. Such as event viewer
entries, performance counters etc. For example. MOM can be configured to watch
for a specific performance counter in a server and send an alert when the
specific counters crosses a threshold. The alert is normally delivered to MOM
operator's console. Configuration is done through MOM admin console.
New version of MOM is called SCOM (System Center Operations Manager).
Custom scripts & tasks can be written using VBScript, JScript etc.
New version of MOM is called SCOM (System Center Operations Manager).
Custom scripts & tasks can be written using VBScript, JScript etc.
38. What
is meant by HT in P-IV HT system?
Ans. This technology
states that it can accept multiple thread at one shot which it not possible in
normal P4 structure, so the speed increase in HT Processor.
39. What
is RAS Server? Mention its Uses?
Ans. RAS (Remote Authentication Server). It is
mainly used to authenticate the user logging into the network through internet
example VPN.40. The process of transforming one bit pattern into
another by bit-wise operations is called
1. Masking 2. Pruning
3. Biting 4. Chopping
Ans. It is called masking.
In masking you select a bit pattern and do bit wise OR or AND operation to set a particular bit of a no.
e.g. in a 4 bit no, you have to set the LSB to be 1 always. Then you take mask as 0001 and do OR operation
x|0001
if the bit is set to be 0 always then mask = 1110 and do AND operation
x&1110
In masking you select a bit pattern and do bit wise OR or AND operation to set a particular bit of a no.
e.g. in a 4 bit no, you have to set the LSB to be 1 always. Then you take mask as 0001 and do OR operation
x|0001
if the bit is set to be 0 always then mask = 1110 and do AND operation
x&1110
41. What
is the difference between blocking and waiting state of process?
Ans. A blocking state is the state in which the process
is waiting for some operation to get completed. It can be an I/O operation or
some Inter-Process-communication. The process can not execute further without
these signals.
A waiting state is the state in which the process is ready to run but the processor is not idle.
When the operation on the blocked process complete, it will move in to the waiting state.
A waiting state is the state in which the process is ready to run but the processor is not idle.
When the operation on the blocked process complete, it will move in to the waiting state.
42. What
is distributed Systems?
43. Why
thread is called as a lightweight process?
Ans. thread is a lightweight process because it simply
divides a process into various sub processes....each sub process completes
specific task and these threads run simultaneously (parallel) resulting in speedy
process completion & reduced resource usage. Hence less load on O.S.
44. What
resources are used when a thread created? How do they differ from those when a
process is created?
Ans. Thread:
In case of thread only one copy of resources are made. means Resources are shared between different threads. This is done on a synchronized basis.
Process:
A separate instances of resources are allotted to different processes at same time and they are not synchronized.
In case of thread only one copy of resources are made. means Resources are shared between different threads. This is done on a synchronized basis.
Process:
A separate instances of resources are allotted to different processes at same time and they are not synchronized.
45. Define Demand Paging, Page fault interrupt, and Trashing?
Ans. Demand Paging: Demand
paging is the paging policy that a page is not read into memory until it is
requested, that is, until there is a page fault on the page.
Page fault interrupt: A page fault interrupt occurs when a memory reference is made to a
page that is not in memory.
The present bit in the page table entry will be
found to be off by the virtual memory hardware and it will signal an interrupt.
Trashing: The problem of
many page faults occurring in a short time, called “page thrashing,”
46. What
do you mean by deadlock?
Ans. Deadlock is a situation where a group of processes are all blocked and
none of them can become unblocked until one of the other becomes unblocked.
The simplest deadlock is two processes each of which
is waiting for a message from the other.
47. Give
an example of microkernel?
48. What
is DRAM? In which form does it store data?
Ans. DRAM forms the
Physical Memory of the PC. The process of recharging described in the earlier
post is known as a Refreshing Cycle.
49. How
chkdsk command works?
Ans. Check disk is a command in
DOS and Microsoft Windows systems which verifies a hard disk or a floppy disk
for file system integrity. It is similar to the fsck command in Unix. By
default, CHKDSK neither fixes errors nor checks for bad sectors. In order to
fix errors while using the command line interface, the /F parameter should be
specified. In order to check for and mark bad sectors, the /R parameter should
be specified. Other parameters can be listed by typing the command chkdsk /?
50. What
are the basic functions of an operating system?
Ans. Operating system controls and coordinates the use
of the hardware among the various applications programs for various uses.
Operating system acts as resource allocator and manager. Since there are many
possibly conflicting requests for resources the operating system must decide
which requests are allocated resources to operating the computer system
efficiently and fairly. Also operating system is control program which controls
the user programs to prevent errors and improper use of the computer. It is
especially concerned with the operation and control of I/O devices.
51.
Difference between Logical and Physical Address Space?
Ans. The concept of a logical address
space that is bound to a separate physical address space is
central to proper memory management.
Logical address –
generated by the CPU; also referred to as virtual address.
Physical address – address
seen by the memory unit.
->Logical and physical addresses are the same in
compile-time and load-time address-binding schemes; logical (virtual) and
physical addresses differ in execution-time address-binding scheme
52. what
is page fault?
Ans. Page fault is the situation
when the CPU want to access a page from the cache but it doesn't find there. So
it has to go to the main memory for the particular page. This is Page fault.
53. Root
Directory.
Ans. The root directory of disk should be placed
1. at a fixed address in main memory
2. at a fixed location on disk
3. anywhere on the disk
4. at a fixed location on the system disk
1. at a fixed address in main memory
2. at a fixed location on disk
3. anywhere on the disk
4. at a fixed location on the system disk
54. Which
file extension is responsible for holding address book in outlook express?
Ans. Outlook Express is a no-cost, basic e-mail program
that is included with Microsoft Internet Explorer. Outlook Express stores
contacts in a Microsoft Windows® Address Book file with an extension of .wab.
The name of the file is based on your Windows logon name. For example, Lori
Kane may have a Windows logon name of lorik, and her Windows Address Book file
would be lorik.wab. This file is saved at C:\Documents and Settings\<user
name>\Application Data\Microsoft\Address Book. -Referene: Microsoft Office
Online.
55. What
is the difference between outlook exp and ms outlook?
In MS-Outlook Express support IMP And IMP4 mail protocol, its store large database, more secure support all format mail like Richtext, HTML, word editing, Spell Check, Ms-outlook has several other features also to manage our daily routing work in office, for example diary, reminders, etc.
Outlook exp did not support as exchange client, but ms outlook support as exchange client.
56. What
are the main difference between Micro-Controller and Micro- Processor?
Ans. A microcontroller is by
definition a is a computer on a chip. It includes all the necessary parts
(including the memory) all in one IC. You just need to apply the power (and
possibly clock signal) to that device and it starts executing the program
programmed to it. A microcontroller generally has the main CPU core,
ROM/EPROM/EEPROM/FLASH, RAM and some necessary functions (like timers and I/O
controllers) all integrated into one chip. The original idea behind the
microcontroller was to limit the capabilities of the CPU itself, allowing a
complete computer (memory, I/O, interrupts, etc) to fit on the available silicon
real estate.
Microcontrollers are typically used where
processing power isn't so important. More important are generally compact
construction, small size, low power consumption and that those chips are cheap.
For example controlling a microwave oven is easily accomplished with the
smallest of microcontrollers. There is countless number of small electronic
devices which are nowadays based on microcontroller. A modern home can include
easily tens or hundreds of microcontrollers, as almost every modern device
which has electronics have a microcontroller (or more than one) inside.
Microprocessor is generally just the CPU core
itself, although nowadays it might have some accessory parts also integrated to
the same chip
57. I
have deleted a file from recycle bin but i want to use that file how can i
restore that file? I have already used system restore for the same but the file
couldn't be restored?
1. Restore from last back.
2. User Recycler folder. Start-->RUN-->type c:recycler --> type FTYPE
58. Differentiate between RAM and ROM?
Ans. Semiconductor memories are of two types: RAM
(random access memory) and ROM (read only memory).
RAM is a read/write memory. Information can be
written into and read from a RAM. It is volatile memory.
It stores information so long as power supply is
on.
ROM is permanent type memory. Its contents are not
lost when power supply goes off. the user cannot write into a ROM.Its contents
are decided by the manufacturer and written at the time of manufacture.
Programmable ROMs are also available. They are
called PROMs.
59.
Difference between TCP and RDP, DOMAIN and OU. DOMAIN CONTROLLER and GLOBAL
CATALOG?
Remote Desktop Protocol: Used for accessing the Desktop Remotely
2.Domain: A security boundary for the network
Organizational Unit: A part of Active Directory used to Organise and Manage the objects of AD
3.Domain Controller: Used for managing the objects in the domain
Global Catalog Server: A Domain Controller promoted to be a CG, holds partial replica of every object in the forest.
60. What is use of ntbootdd.sys file?
Ans. this file is used when you have a scsi drive,
basically this file stores the scsi driver if it is not available with
windows os.
61. What
is difference between Global catalog and infrastructure master?
Ans. 1. GC holds group membership of universal group. while Infrastructure
hold group information in domain level. Global Catalog server holds a partial
replica of every object in the forest. Global Catalog server holds a partial
replica of every object in the forest.
2. We can't set infrastucture mastre and GC together on same DC. Infrastructure
Master contains the references to objects in the forest.
62. What
is the main component of operating system?
Shell is a interface between application program and kernel whenever application program wants some work to be done It contacts kernel and kernel in turn perform work with the help of device drivers .thus we can say
Kernel is an interface between hardware and shell.
Kernel uses device drivers to control microcontroller card of peripheral device and in turn work is being accomplished.
Application program -> [shells ->kernel ->device driver -> controller card -> physical hardware]
63. What
are the major differences between windows XP and Windows 2000 operating
systems?
Ans. major differences between win2000 Professional and
WinXp Professional that are: 1.REMOTE DESKTOP: we can remotely connect WinXp
machine from any windows system like win98, win2000, winxp and win2003
2.SHARING NETWORK CONNECTION: we can share easily our network resources to
other people those r resided in other network. {Whereas in win2000, we can
share our internet connection to our local network only.} 3. FIREWALL: we can
restrict deny the people in the internet who r trying to access our resources
and wanton corrupt our systems like Hackers. 4. SOFTWARE RESTRICTIONS In Group
Policy: we can restrict the particular users such that they cannot use particular
software using group policies. 5. Past switching user login: multiple users can
login with ought logging off already login user; with ought losing any data in
the same WinXp machine. 6. Version Confliction: we can install multiple
versions of same application in one Machine. (Even we can install in win98,
win2000, some where in the middle, we face the problem.)
64. Why
do multi-tasking operating systems in a single user machines today?
Ans. The need for multi-tasking operating systems
including Unix, Linux, Windows xp , 2000 etc. in a single user machines is for
simultaneous access to many applications. For example while using internet
explorer wants attach some document file(.doc) it is not updated then he needs
to open the Ms-Word, edit it and save it then attach it and simultaneously he
can open the pdf file with acrobat reader for referring some digitized book
etc. And can search for some information with google it is possible only
because of multi-tasking operating systems.
65.
Different types of Real-Time Scheduling?
Ans. Hard real-time systems –
required to complete a critical task within a guaranteed amount of time.
Soft real-time computing
– requires that critical processes receive priority over less fortunate ones.
I think Hard Real time and Soft Real time is type of real time system.
But Question is Scheduling type.
I think scheduling types are:
a. Primitive priority based scheduling
B. Non-Primitive scheduling
C. Round Robin scheduling
66. What
are Dump terminals in UNIX?
Ans. In short dump terminals are the terminals which are
connected with a centralized CPU and lack individual CPUs.
67. What
is a Real-Time System?
Ans. A real time process is a process that must respond
to the events within a certain time period. A real time operating system is an
operating system that can run real time processes successfully
68.
Describe different job scheduling in operating systems?
Ans. Scheduling is the activity of the deciding when
process will receive the resources they request.
FCFS: --- FCSFS stands for First Come First Served.
In FCFS the job that has been waiting the longest is served next.
Round Robin Scheduling: ---Round Robin scheduling
is a scheduling method where each process gets a small quantity of time to run
and then it is preempted and the next process gets to run. This is called
time-sharing and gives the effect of all the processes running at the same time
Shortest Job First: -- The Shortest job First
scheduling algorithm is a nonpreemptive scheduling algorithm that chooses the
job that will execute the shortest amount of time.
Priority Scheduling: ---Priority scheduling is a
scheduling method where at all times the highest priority process is assigned
the resource.
69. What
is hard disk and what is its purpose?
Ans. Hard disk is the secondary storage device, which
holds the data in bulk, and it holds the data on the magnetic medium of the
disk.Hard disks have a hard platter that holds the magnetic medium, the
magnetic medium can be easily erased and rewritten, and a typical desktop
machine will have a hard disk with a capacity of between 10 and 40 gigabytes.
Data is stored onto the disk in the form of files.
70. What is
cache memory?
Ans. Cache memory is random access memory (RAM) that a
computer microprocessor can access more quickly than it can access regular RAM.
As the microprocessor processes data, it looks first in the cache memory and if
it finds the data there (from a previous reading of data), it does not have to
do the more time-consuming reading of data from larger memory.
71. Why
paging is used?
Ans. Paging is solution to external fragmentation problem which is to permit
the logical address space of a process to be noncontiguous, thus allowing a
process to be allocating physical memory wherever the latter is available.
72.
Difference between Primary storage and secondary storage?
Ans. Main memory: – only large storage media that the CPU can access directly.
Secondary storage: – extension of main memory that provides large nonvolatile storage
capacity.
73. What
is CPU Scheduler?
Ans. Selects from among the processes in memory that are
ready to execute, and allocates the CPU to one of them.
->CPU scheduling decisions may take place when a
process:
1. Switches from running to waiting state.
2. Switches from running to ready state.
3. Switches from waiting to ready.
4. Terminates.
->Scheduling under 1 and 4 is no preemptive.
->All other scheduling is preemptive
74.
Recovery from Deadlock?
Ans. Process
Termination:
->Abort all deadlocked processes.
->Abort one process at a time until the deadlock
cycle is eliminated.
->In which order should we choose to abort?
Priority of the process.
How long process has computed, and how much longer
to completion.
Resources the process has used.
Resources process needs to complete.
How many processes will need to be terminated?
Is process interactive or batch?
Resource Preemption:
->Selecting a victim – minimize cost.
->Rollback – return to some safe state, restart
process for that state.
->Starvation – same process may always be picked
as victim, include number of rollback in cost factor
75. What
is Memory-Management Unit (MMU)?
Ans. ->Hardware device that maps virtual to physical
address.
In MMU scheme, the value in the relocation register
is added to every address generated by a user process at the time it is sent to
memory.
->The user program deals with logical
addresses; it never sees the real physical addresses.
76. What
are Dynamic Loading, Dynamic Linking and Overlays?
Ans. Dynamic Loading:
->Routine is not loaded until it is called
->Better memory-space utilization; unused
routine is never loaded.
->Useful when large amounts of code are needed
to handle infrequently occurring cases.
->No special support from the operating system
is required implemented through program design.
Dynamic Linking:
->Linking postponed until execution time.
->Small piece of code, stub, used to
locate the appropriate memory-resident library routine.
->Stub replaces itself with the address of the
routine, and executes the routine.
->Operating system needed to check if routine is
in processes’ memory address.
->Dynamic linking is particularly useful for
libraries.
Overlays:
->Keep in memory only those instructions and
data that are needed at any given time.
->Needed when process is larger than amount of
memory allocated to it.
->Implemented by user, no special support needed
from operating system, programming design of overlay structure is complex
77. What
are the different Dynamic Storage-Allocation methods?
Ans. How to satisfy a request of size n from a
list of free holes?
First-fit:
Allocate the first hole that is big enough.
Best-fit: Allocate
the smallest hole that is big enough; must search entire list, unless
ordered by size. It produces the smallest leftover hole.
Worst-fit:
Allocate the largest hole; must also search entire list. Produces
the largest leftover hole.
First-fit and best-fit are better than worst-fit in
terms of speed and storage utilization.
78. What
is fragmentation? Different types of fragmentation?
Ans. Fragmentation occurs in a dynamic memory allocation
system when many of the free blocks are too small to satisfy any request.
External Fragmentation: External Fragmentation happens when a dynamic memory allocation
algorithm allocates some memory and a small piece is left over that cannot be
effectively used. If too much external fragmentation occurs, the amount of
usable memory is drastically reduced.
Total memory space exists to satisfy a request, but
it is not contiguous
Internal Fragmentation: Internal fragmentation is the space wasted inside of allocated memory
blocks because of restriction on the allowed sizes of allocated blocks.
Allocated memory may be slightly larger than
requested memory; this size difference is memory internal to a partition, but
not being used
Reduce external fragmentation by compaction
->Shuffle memory contents to place all free
memory together in one large block.
->Compaction is possible only if
relocation is dynamic, and is done at execution time.
79. Under
what circumstances do page faults occur? Describe the actions taken by the
operating system when a page fault occurs?
Ans. A page fault occurs when an access to a page that
has not been brought into main memory takes place. The operating system
verifies the memory access, aborting the program if it is invalid. If it is
valid, a free frame is located and I/O is requested to read the needed page
into the free frame. Upon completion of I/O, the process table and page table
are updated and the instruction is restarted.
80. What
is the cause of thrashing? How does the system detect thrashing? Once it
detects thrashing, what can the system do to eliminate this problem?
Ans. Thrashing is caused by under allocation of the
minimum number of pages required by a process, forcing it to continuously page
fault. The system can detect thrashing by evaluating the level of CPU
utilization as compared to the level of multiprogramming. It can be eliminated
by reducing the level of multiprogramming.
ANS:- There are many features in
windows 2003 domain controller as compares to
Windows 2000 DC like
1- We can create cross forest link trust.
2- Can rename domain name.
3- More scaleable
4- Have the features of ADAM (active directory
application mode)
5- Support more processor compares to windows 2000
If you need more details contact me I can give you
more stuff of Windows 2003,
Active directory, MS Exchange server.
82: What is the difference between windows server 2003 And 2000 Server ?
ANS:-
A) In 2000 we cannot rename domain whereas in 2003
we can rename Domain
B) In 2000 it supports of 8 processors and 64 GB
RAM (In 2000 Advance Server) whereas in 2003 supports up to 64 processors and
max of 512GB RAM
C)2000 Supports IIS 5.0 and 2003 Supports IIS6.0
D) 2000 doesn’t support Dot net whereas 2003 Supports
Microsoft .NET 2.0
E) 2000 has Server and Advance Server editions
whereas 2003 has Standard, Enterprise
F) 2000 doesn’t have any 64 bit server operating
system whereas 2003 has 64 bit server operating systems (Windows Server 2003
X64 Std and Enterprise Edition)
G) 2000 has basic concept of DFS (Distributed File
systems) with defined roots whereas 2003 has Enhanced DFS support with multiple
roots.
H) In 2000 there is complexality in administering
Complex networks whereas 2003 is easy administration in all & Complex
networks
I) In 2000 we can create 1 million users and in
2003 we can create 1 billion users.
J) In 2003 we have concept of Volume shadow copy
service which is used to create hard disk snap shot which is used in Disaster
recovery and 2000 doesn’t have this service.
K) In 2000 we don’t have end user policy
management, whereas in 2003 we have a End user policy management which is done
in GPMC (Group policy management console).
L) In 2000 we have cross domain trust relation ship
and 2003 we have Cross forest trust relationship.
M) 2000 Supports 4-node clustering and 2003
supports 8-node clustering.
N) 2003 has High HCL Support (Hardware
Compatibility List) issued by Microsoft
O) Code name of 2000 is Win NT 5.0 and Code name of
2003 is Win NT 5.1
P) 2003 has service called ADFS (Active Directory
Federation Services) which is used to communicate between branches with safe
authentication.
Q) In 2003 their is improved storage management
using service File Server Resource Manager (FSRM)
R) 2003 has service called Windows Share point
Services (It is an integrated portfolio of collaboration and communication
services designed to connect people, information, processes, and systems both
within and beyond the organizational firewall.)
S) 2003 has Improved Print management compared to
2000 server
T) 2003 has telnet sessions available.
U) 2000 supports IPV4 whereas 2003 supports IPV4
and IPV6
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