Operating System Tutorial

Operating System Tutorial Types of Operating System Evolution of Operating System Functions of Operating System Operating System Properties Operating System Services Components of Operating System Needs of the Operating System

Operating Systems

Linux Operating System Unix Operating System Ubuntu Operating System Chrome Operating Systems Fedora Operating System MAC Operating System MS Windows Operating System Solaris Operating System Cooperative Operating System CorelDRAW Operating System CentOS FreeBSD Operating Systems Batch Operating System MS-DOS Operating System Commercial Mobile Operating Systems


Difference Between Multi-programming and Multitasking Difference between C-LOOK and C-SCAN Difference between Rotational Latency and Disk Assess Time Trap vs Interrupt Difference between C-SCAN and SSTF Difference between SCAN and FCFS Difference between Seek Time and Disk Access Time Difference between SSTF and LOOK Difference between Process and Program in the Operating System Difference between Protection and Security in Operating System

How To

How to implement Monitors using Semaphores How to Install a Different Operating System on a PC


What is Kernel and Types of Kernel What is DOS Operating System What is Thread and Types of Thread What is Process Scheduler and Process Queue What is Context Switching What is CPU Scheduling What is Producer-Consumer Problem What is Semaphore in Operating System Monitors in Operating System What is Deadlock What is Paging and Segmentation What is Demand Paging What is Virtual Memory What is a Long term Scheduler What is Page Replacement in Operating System What is BSR Mode What is Convoy Effect What is Job Sequencing in Operating System Why is it critical for the Scheduler to distinguish between I/O-bound and CPU-bound programs Why is there a Need for an Operating System


Process Management Process State Scheduling Algorithm FCFS (First-come-First-Serve) Scheduling SJF (Shortest Job First) Scheduling Round-Robin CPU Scheduling Priority Based Scheduling HRRN (Highest Response Ratio Next) Scheduling Process Synchronization Lock Variable Mechanism TSL Mechanism Turn Variable Mechanism Interested Variable Mechanism Deadlock Avoidance Strategies for Handling Deadlock Deadlock Prevention Deadlock Detection and Recovery Resource Allocation Graph Banker’s Algorithm in Operating System Fixed Partitioning and Dynamic Partitioning Partitioning Algorithms Disk Scheduling Algorithms FCFS and SSTF Disk Scheduling Algorithm SCAN and C-SCAN Disk Scheduling Algorithm Look and C-Look Disk Scheduling Algorithm File in Operating System File Access Methods in Operating System File Allocation Method Directory Structure in Operating System N-Step-SCAN Disk Scheduling Feedback Queue in Operating System Contiguous Memory Allocation in Operating System Real-time Operating System Starvation in Operating System Thrashing in Operating System 5 Goals of Operating System Advantages of Operating System Advantages of UNIX Operating System Bit Vector in Operating System Booting Process in Operating System Can a Computer Run Without the Operating System Dining Philosophers Problem in Operating System Free Space Management in Operating System Inter Process Communication in Operating System Swapping in Operating System Memory Management in Operating System Multiprogramming Operating System Multitasking Operating Systems Multi-user Operating Systems Non-Contiguous Memory Allocation in Operating System Page Table in Operating System Process Scheduling in Operating System Segmentation in Operating System Simple Structure in Operating System Single-User Operating System Two Phase Locking Protocol Advantages and Disadvantages of Operating System Arithmetic operations in binary number system Assemblers in the operating system Bakery Algorithm in Operating System Benefits of Ubuntu Operating System CPU Scheduling Criteria in Operating System Critical Section in Operating System Device Management in Operating System Linux Scheduler in Operating System Long Term Scheduler in Operating System Mutex in Operating System Operating System Failure Peterson's Solution in Operating System Privileged and Non-Privileged Instructions in Operating System Swapping in Operating System Types of Operating System Zombie and Orphan Process in Operating System 62-bit operating system Advantages and Disadvantages of Batch Operating System Boot Block and Bad Block in Operating System Contiguous and Non - Contiguous Memory Allocation in Operating System Control and Distribution Systems in Operations Management Control Program in Operating System Convergent Technologies in Operating System Convoy Effect in Operating System Copy Operating Systems to SSD Core Components of Operating System Core of UNIX Operating System Correct Value to return to the Operating System Corrupted Operating System Cos is Smart Card Operating System Cosmos Operating Systems Examples Generation of Operating System Hardware Solution in Operating System Process Control Block in Operating System Function of Kernel in Operating System Operating System Layers History of Debian Operating Systems Branches and Architecture of Debian Operating Systems Features and Packages of Debian Operating Systems Installation of Operating System on a New PC Organizational Structure and Development in Debian Operating Systems User Interface in Operating System Types Of Memory in OS Operating System in Nokia Multilevel Paging in OS Memory Mapping Techniques in OS Memory Layout of a Process in Operating System Hardware Protection in Operating System Functions of File Management in Operating System Core of Linux Operating System Cache Replacement Policy in Operating System Cache Line and Cache Size in Operating System What is Memory Mapping? Difference Between Network Operating System And Distributed Operating System What is the difference between a Hard link and a Soft Link? Principles of Preemptive Scheduling Process Scheduling Algorithms What is NOS? What is the Interrupt I/O Process? What is Time Sharing OS What is process termination? What is Time-Sharing Operating System What is Batch File File system manipulation What is Message-passing Technique in OS Logical Clock in Distributed System

Difference between Seek Time and Disk Access Time in Disk Scheduling

Seek Time

The time taken for the hard disk controller to detect a specific piece of recorded data is known as the seek time. The amount of time it takes to find the head depends on where it is when the read/write request is issued. The read/write head of a disc drive moves to the correct place when something is read or written to it. Seeking refers to the physical location of the read/write head on the disk. Discovery time is the time it takes for a disk's read/write head to move from one disk to another. Due to the varying distance between the start point and where the read/write vertex is directed to travel, the search time for a particular disk may vary. As a result, seek time is usually expressed as average search time. Track to track and entire stroke are two more methods to quantify seek time.

  • The read/write time taken to search or search between neighboring tracks is called track to track. It is measured in milliseconds (ms), which ranges from 2 to 4 ms but can be as short as 1 ms.
  • The time taken to search the entire disk is called full stroke. A full stroke is also measured in milliseconds, and a search time of less than 10ms for hard disks is generally considered sufficient.

The operating system instructs the drive controller firmware to get data from a hard disc, which causes the read/write head to travel to the location where the data is stored. Switching between tracks necessitates the head actuator moving the access arm, which takes some time. This period is known as the discovery time. This varies depending on the distance between the tracks and the distance from its origin at the time of each read/write instruction.

Disk Access Time

The overall time taken by the computer to perform a read/write request and then obtain the relevant data from disc storage is known as disc access time. Disk access time is divided into two parts. The search time, which is when the read and write branch searches the required track, is the first component. Latency, or wait time, is the time it takes for the head write arm to wait for the required sector on the track to rotate around. The time it takes to access data on drives is measured in milliseconds. This is, however, far slower than the processing rates of CPUs. Although I/O is still sluggish, it cannot keep up with the advances in CPU performance.

There are two elements to disk access time:

  • Data Transfer Time
  • Access Time

Data Transfer Time

The time taken to transmit data between the system and the disk is known as the data transfer time. There are two types of data transfer time:

  • Internal Transfer Rate: This is the time it takes for data to go from the disc surface to the hard disc cache.
  • The time it takes to transport data between the hard disc cache and the system is known as the external transfer rate.

Access Time

The preparation time before the actual data transfer is denoted as Access Time. The read/write head, for example, is on track 1, but we need to read data from a different track or segment. As a result, before the actual transfer, the read/write head will relocate to the data block position. This lag is referred to as Access Time.


S no.Seek TimeDisk Time
1.The time it takes for the head to travel from the current track to the one with data is known as seek time.The time it takes for a computer to perform a read/write request and obtain the data it needs is known as disc access time.
2.Because seek time is a subset of disc access time, it is always smaller than disc access time.When compared to Seek time, disc access time is relatively long.
3.A data transmission is not taken into account while calculating seek time.The time it takes to transmit data from one disc to another is referred to as disc access time.
4.The amount of time it takes to seek varies greatly based on the distance between the present and ultimate positions and how it is ordered to proceed.The two components of disc access time are access time and data transfer time.
5.Depending on the RPS and drive grade, the seek time is normally between 10 and 20 milliseconds.If we can cut access time and data transfer time, we can reduce disc access time.
6.Average Seek Time is a metric for determining how long it takes to find something.Seek time plus rotational latency plus data transfer time equals disc access time.