This document discusses directory implementation and file allocation methods in file systems. It describes two common directory implementation algorithms: linear lists and hash tables. It also outlines three file allocation methods: contiguous allocation, linked allocation, and indexed allocation. Each method is explained along with its advantages and disadvantages.
n computer operating systems, demand paging is a method of virtual memory management. In a system that uses demand paging, the operating system copies a disk page into physical memory only if an attempt is made to access it and that page is not already in memory
This Presentation is for Memory Management in Operating System (OS). This Presentation describes the basic need for the Memory Management in our OS and its various Techniques like Swapping, Fragmentation, Paging and Segmentation.
n computer operating systems, demand paging is a method of virtual memory management. In a system that uses demand paging, the operating system copies a disk page into physical memory only if an attempt is made to access it and that page is not already in memory
This Presentation is for Memory Management in Operating System (OS). This Presentation describes the basic need for the Memory Management in our OS and its various Techniques like Swapping, Fragmentation, Paging and Segmentation.
LANGUAGE PROCESSING SYSTEM
COMPILER DESIGN- ARCHITECTURE
INTERPRETER
ROLE OF COMPILER & INTERPRETER
COMPARISION OF INTERPRETER & COMPILER
PURE AND IMPUTER INTERPRETER
P-CODE COMPILERS
Segmentation topic is presented in a most easy way.
Segmentation is a user view of memory in Operating System. Segmentation is one of the most common ways to achieve memory protection. In a computer system using segmentation, an instruction operand that refers to a memory location includes a value that identifies a segment and an offset within that segment.
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some PagesAre Not in Main Memory
Steps in Handling a Page Fault
This presentation describes about the various memory allocation methods like first fit, best fit and worst fit in memory management and also about fragmentation problem and solution for the problem.
LANGUAGE PROCESSING SYSTEM
COMPILER DESIGN- ARCHITECTURE
INTERPRETER
ROLE OF COMPILER & INTERPRETER
COMPARISION OF INTERPRETER & COMPILER
PURE AND IMPUTER INTERPRETER
P-CODE COMPILERS
Segmentation topic is presented in a most easy way.
Segmentation is a user view of memory in Operating System. Segmentation is one of the most common ways to achieve memory protection. In a computer system using segmentation, an instruction operand that refers to a memory location includes a value that identifies a segment and an offset within that segment.
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some PagesAre Not in Main Memory
Steps in Handling a Page Fault
This presentation describes about the various memory allocation methods like first fit, best fit and worst fit in memory management and also about fragmentation problem and solution for the problem.
Useful documents for engineering students of CSE, and specially for students of aryabhatta knowledge university, Bihar (A.K.U. Bihar). It covers following topics, File concept, access methods, directory structure
Can be built on top of base methods
General involve creation of an index for the file
Keep index in memory for fast determination of location of data to be operated on (consider UPC code plus record of data about that item)
If too large, index (in memory) of the index (on disk)
IBM indexed sequential-access method (ISAM)
Small master index, points to disk blocks of secondary index
File kept sorted on a defined key
All done by the OS
VMS operating system provides index and relative files as another example .
Similar to Directory implementation and allocation methods (20)
Paketo Buildpacks : la meilleure façon de construire des images OCI? DevopsDa...Anthony Dahanne
Les Buildpacks existent depuis plus de 10 ans ! D’abord, ils étaient utilisés pour détecter et construire une application avant de la déployer sur certains PaaS. Ensuite, nous avons pu créer des images Docker (OCI) avec leur dernière génération, les Cloud Native Buildpacks (CNCF en incubation). Sont-ils une bonne alternative au Dockerfile ? Que sont les buildpacks Paketo ? Quelles communautés les soutiennent et comment ?
Venez le découvrir lors de cette session ignite
Custom Healthcare Software for Managing Chronic Conditions and Remote Patient...Mind IT Systems
Healthcare providers often struggle with the complexities of chronic conditions and remote patient monitoring, as each patient requires personalized care and ongoing monitoring. Off-the-shelf solutions may not meet these diverse needs, leading to inefficiencies and gaps in care. It’s here, custom healthcare software offers a tailored solution, ensuring improved care and effectiveness.
How to Position Your Globus Data Portal for Success Ten Good PracticesGlobus
Science gateways allow science and engineering communities to access shared data, software, computing services, and instruments. Science gateways have gained a lot of traction in the last twenty years, as evidenced by projects such as the Science Gateways Community Institute (SGCI) and the Center of Excellence on Science Gateways (SGX3) in the US, The Australian Research Data Commons (ARDC) and its platforms in Australia, and the projects around Virtual Research Environments in Europe. A few mature frameworks have evolved with their different strengths and foci and have been taken up by a larger community such as the Globus Data Portal, Hubzero, Tapis, and Galaxy. However, even when gateways are built on successful frameworks, they continue to face the challenges of ongoing maintenance costs and how to meet the ever-expanding needs of the community they serve with enhanced features. It is not uncommon that gateways with compelling use cases are nonetheless unable to get past the prototype phase and become a full production service, or if they do, they don't survive more than a couple of years. While there is no guaranteed pathway to success, it seems likely that for any gateway there is a need for a strong community and/or solid funding streams to create and sustain its success. With over twenty years of examples to draw from, this presentation goes into detail for ten factors common to successful and enduring gateways that effectively serve as best practices for any new or developing gateway.
Into the Box Keynote Day 2: Unveiling amazing updates and announcements for modern CFML developers! Get ready for exciting releases and updates on Ortus tools and products. Stay tuned for cutting-edge innovations designed to boost your productivity.
Listen to the keynote address and hear about the latest developments from Rachana Ananthakrishnan and Ian Foster who review the updates to the Globus Platform and Service, and the relevance of Globus to the scientific community as an automation platform to accelerate scientific discovery.
Globus Compute wth IRI Workflows - GlobusWorld 2024Globus
As part of the DOE Integrated Research Infrastructure (IRI) program, NERSC at Lawrence Berkeley National Lab and ALCF at Argonne National Lab are working closely with General Atomics on accelerating the computing requirements of the DIII-D experiment. As part of the work the team is investigating ways to speedup the time to solution for many different parts of the DIII-D workflow including how they run jobs on HPC systems. One of these routes is looking at Globus Compute as a way to replace the current method for managing tasks and we describe a brief proof of concept showing how Globus Compute could help to schedule jobs and be a tool to connect compute at different facilities.
Cyaniclab : Software Development Agency Portfolio.pdfCyanic lab
CyanicLab, an offshore custom software development company based in Sweden,India, Finland, is your go-to partner for startup development and innovative web design solutions. Our expert team specializes in crafting cutting-edge software tailored to meet the unique needs of startups and established enterprises alike. From conceptualization to execution, we offer comprehensive services including web and mobile app development, UI/UX design, and ongoing software maintenance. Ready to elevate your business? Contact CyanicLab today and let us propel your vision to success with our top-notch IT solutions.
How Recreation Management Software Can Streamline Your Operations.pptxwottaspaceseo
Recreation management software streamlines operations by automating key tasks such as scheduling, registration, and payment processing, reducing manual workload and errors. It provides centralized management of facilities, classes, and events, ensuring efficient resource allocation and facility usage. The software offers user-friendly online portals for easy access to bookings and program information, enhancing customer experience. Real-time reporting and data analytics deliver insights into attendance and preferences, aiding in strategic decision-making. Additionally, effective communication tools keep participants and staff informed with timely updates. Overall, recreation management software enhances efficiency, improves service delivery, and boosts customer satisfaction.
Accelerate Enterprise Software Engineering with PlatformlessWSO2
Key takeaways:
Challenges of building platforms and the benefits of platformless.
Key principles of platformless, including API-first, cloud-native middleware, platform engineering, and developer experience.
How Choreo enables the platformless experience.
How key concepts like application architecture, domain-driven design, zero trust, and cell-based architecture are inherently a part of Choreo.
Demo of an end-to-end app built and deployed on Choreo.
Enhancing Project Management Efficiency_ Leveraging AI Tools like ChatGPT.pdfJay Das
With the advent of artificial intelligence or AI tools, project management processes are undergoing a transformative shift. By using tools like ChatGPT, and Bard organizations can empower their leaders and managers to plan, execute, and monitor projects more effectively.
We describe the deployment and use of Globus Compute for remote computation. This content is aimed at researchers who wish to compute on remote resources using a unified programming interface, as well as system administrators who will deploy and operate Globus Compute services on their research computing infrastructure.
Navigating the Metaverse: A Journey into Virtual Evolution"Donna Lenk
Join us for an exploration of the Metaverse's evolution, where innovation meets imagination. Discover new dimensions of virtual events, engage with thought-provoking discussions, and witness the transformative power of digital realms."
top nidhi software solution freedownloadvrstrong314
This presentation emphasizes the importance of data security and legal compliance for Nidhi companies in India. It highlights how online Nidhi software solutions, like Vector Nidhi Software, offer advanced features tailored to these needs. Key aspects include encryption, access controls, and audit trails to ensure data security. The software complies with regulatory guidelines from the MCA and RBI and adheres to Nidhi Rules, 2014. With customizable, user-friendly interfaces and real-time features, these Nidhi software solutions enhance efficiency, support growth, and provide exceptional member services. The presentation concludes with contact information for further inquiries.
In 2015, I used to write extensions for Joomla, WordPress, phpBB3, etc and I ...Juraj Vysvader
In 2015, I used to write extensions for Joomla, WordPress, phpBB3, etc and I didn't get rich from it but it did have 63K downloads (powered possible tens of thousands of websites).
Quarkus Hidden and Forbidden ExtensionsMax Andersen
Quarkus has a vast extension ecosystem and is known for its subsonic and subatomic feature set. Some of these features are not as well known, and some extensions are less talked about, but that does not make them less interesting - quite the opposite.
Come join this talk to see some tips and tricks for using Quarkus and some of the lesser known features, extensions and development techniques.
Globus Connect Server Deep Dive - GlobusWorld 2024Globus
We explore the Globus Connect Server (GCS) architecture and experiment with advanced configuration options and use cases. This content is targeted at system administrators who are familiar with GCS and currently operate—or are planning to operate—broader deployments at their institution.
2. Directory Implementation
Number of algorithms by using which, the directories can be implemented.
selection of an appropriate directory implementation algorithm may significantly
affect the performance of the system.
classified according to the data structure they are using.
There are mainly two algorithms which are used in these days.
1. Linear list
2. Hash table
3. 1. Linear List
All the files in a directory are maintained as singly linked list.
Each file contains the pointers to the data blocks which are assigned to it and the
next file in the directory.
4. Characteristics of linear list
searching for a unique name is a big concern because traversing the whole list
takes time.
When a new file is created, then the entire list is checked whether the new file
name is matching to a existing file name or not. In case, it doesn't exist, the file can
be created at the beginning or at the end.
The list needs to be traversed in case of every operation (creation, deletion,
updating, etc) on the files therefore the systems become inefficient.
5. 2. Hash Table
It overcome the drawbacks of singly linked list implementation.
This approach suggests to use hash table along with the linked lists.
A key-value pair for each file in the directory gets generated and stored in the hash
table.
The key can be determined by applying the hash function on the file name while
the key points to the corresponding file stored in the directory.
searching becomes efficient
Only hash table entries are checked using the key and if an entry found then the
corresponding file will be fetched using the value.
6.
7. Allocation Methods
There are various methods which can be used to allocate disk space to the files.
Selection of an appropriate allocation method will significantly affect the
performance and efficiency of the system.
Allocation method provides a way in which the disk will be utilized and the files will
be accessed.
following methods which can be used for allocation.
1. Contiguous Allocation
2. Linked Allocation
3. Indexed Allocation
8. 1. Contiguous Allocation
If the blocks are allocated to the file in such a way that all the logical blocks of the
file get the contiguous physical block in the hard disk then such allocation scheme
is known as contiguous allocation.
9. 1. Contiguous Allocation
Advantages
1. It is simple to implement.
2. We will get Excellent read performance.
3. Supports Random Access into files.
Disadvantages
1. The disk will become fragmented (External Fragmentation).
2. It may be difficult to have a file grow (Dynamic Storage allocation problem).
3. Difficult to find space for new file.
10. 2. Linked Allocation
Solves problems of contiguous allocation.
Each file is considered as the linked list of disk blocks.
However, the disks blocks allocated to a particular file need not to be contiguous
on the disk.
Each disk block allocated to a file contains a pointer which points to the next disk
block allocated to the same file.
To create a new file we simply create a new entry in directory.
With linked allocation each directory entry has a pointer to first block of the file.
11.
12. Advantages
1. There is no external fragmentation with linked allocation.
2. Any free block can be utilized in order to satisfy the file block requests.
3. File can continue to grow as long as the free blocks are available.
4. Directory entry will only contain the starting block address.
Disadvantages
1. Random Access is not provided.
2. Pointers require some space in the disk blocks.
3. Any of the pointers in the linked list must not be broken otherwise the file will get
corrupted.
4. Need to traverse each block.
13. File Allocation Table
File Allocation Table overcomes this drawback of linked list allocation in linked
allocation.
a file allocation table is maintained at the beginning of disk volume.
Table has one entry for each disk block and indexed by block number.
Directory entry contains block number of the first block of the file.
The table entry indexed by that block number contains the block number of next
block in the file.
This chain continues until it reaches the last block.
14.
15. 3.Indexed allocation
The more the number of blocks, the more will be the size of FAT.
need to allocate more space to a file allocation table.
file allocation table needs to be cached therefore it is impossible to have as many
space in cache.
Indexed allocation scheme stores all the disk pointers in one of the blocks called as
indexed block.
Indexed block doesn't hold the file data, but it holds the pointers to all the disk
blocks allocated to that particular file.
Directory entry will only contain the index block address.
16.
17. Advantages
1. Supports direct access
2. A bad data block causes the lost of only that block.
3. No external fragmentation
Disadvantages
1. A bad index block could cause the lost of entire file.
2. Size of a file depends upon the number of pointers, a index block can hold.
3. Having an index block for a small file is totally wastage.
4. More pointer overhead