File systems organize and store data on various storage media like hard drives. They consist of structures like directories and files to track allocated space, file names and locations. Key functions include managing free space, directories, and file storage locations. Common file systems include FAT, NTFS, disk, flash, tape, database, network and special purpose file systems. File systems use inodes, directories, block allocation maps and other metadata to organize and track files.
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.
Memory management is the act of managing computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time
Operating System
Topic Memory Management
for Btech/Bsc (C.S)/BCA...
Memory management is the functionality of an operating system which handles or manages primary memory. Memory management keeps track of each and every memory location either it is allocated to some process or it is free. It checks how much memory is to be allocated to processes. It decides which process will get memory at what time. It tracks whenever some memory gets freed or unallocated and correspondingly it updates the status.
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.
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.
Memory management is the act of managing computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time
Operating System
Topic Memory Management
for Btech/Bsc (C.S)/BCA...
Memory management is the functionality of an operating system which handles or manages primary memory. Memory management keeps track of each and every memory location either it is allocated to some process or it is free. It checks how much memory is to be allocated to processes. It decides which process will get memory at what time. It tracks whenever some memory gets freed or unallocated and correspondingly it updates the status.
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.
Overview of Mass Storage Structure
Disk Structure
Disk Attachment
Disk Scheduling
Disk Management
Swap-Space Management
RAID Structure
Disk Attachment
Stable-Storage Implementation
Tertiary Storage Devices
Operating System Issues
Performance Issues
INTRODUCTION
WHAT IS OSI?
OSI MODEL
TYPES OF LAYERS
PHYSICAL LAYER
DATA LINK LAYER
NETWORK LAYER
TRANSPORT LAYER
SESSION LAYER
PRESENTATION LAYER
APPLICATION LAYER
Inter-Process Communication in distributed systemsAya Mahmoud
Inter-Process Communication is at the heart of all distributed systems, so we need to know the ways that processes can exchange information.
Communication in distributed systems is based on Low-level message passing as offered by the underlying network.
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
Overview of Mass Storage Structure
Disk Structure
Disk Attachment
Disk Scheduling
Disk Management
Swap-Space Management
RAID Structure
Disk Attachment
Stable-Storage Implementation
Tertiary Storage Devices
Operating System Issues
Performance Issues
INTRODUCTION
WHAT IS OSI?
OSI MODEL
TYPES OF LAYERS
PHYSICAL LAYER
DATA LINK LAYER
NETWORK LAYER
TRANSPORT LAYER
SESSION LAYER
PRESENTATION LAYER
APPLICATION LAYER
Inter-Process Communication in distributed systemsAya Mahmoud
Inter-Process Communication is at the heart of all distributed systems, so we need to know the ways that processes can exchange information.
Communication in distributed systems is based on Low-level message passing as offered by the underlying network.
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
Case study of BtrFS: A fault tolerant File systemKumar Amit Mehta
A case study of Fault Tolerance features of BTRFS. These slides were prepared for the coursework for a Masters level program at Tallinn University of Technology, Estonia. A lot of materials in the slides are taken from the materials in the public domain. Many thanks to the people on BTRFS IRC Channel.
Comparison of android and black berry forensic techniquesYury Chemerkin
As digital data is omnipresent now, the digital forensics has quickly become a legal necessity. Mobile devices have quickly grown and extend their own features which simplifying makes them less unique. Developers API, SDK, NDK provide great opportunity to build live, DLP or spyware for data extracting.
http://hakin9.org/hakin9-extra-412/
An Advanced SEO presentation that was done for the 2015 BlogPaws conference. Touching on semantic SEO including Latent Semantic Indexing, Schema/Microdata, technical seo and more, all presented in a way that was geared towards bloggers.
At the MnSearch Snippet #13 event held at Spyder Trap in Minneapolis, MN on April 30, 2014, Joe Wilebski presented his slidedeck "Panda, Penguin, Hummingbird."
What One Digital Forensics Expert Found on Hundreds of Hard Drives, iPhones a...Blancco
Do organizations have a defined process for wiping sensitive company information before discarding/reselling old drives and mobile devices?
In this webinar, Randy F. Smith and data security experts from Blancco Technology Group explore the following topics:
- How easily residual data can be recovered from hard drives and mobile devices
- The risks leftover data can pose to organizations
- The most secure ways to wipe company data from end-of-life devices and drives
This presentation was done by Raaj Paatkar at Mumbai SEO & SMM Meetup on March 30, 2014. It covers SEO strategies to rank in Google in face of punishing Google updates like Panda, Penguin and Hummingbird.
Types of File Systems
How does the file system handle security?
Attacks on the file system
How does the file system ensure data integrity?
A file system is an abstraction to store, retrieve and update a set of files. The term also identifies the data structures specified by some of those abstractions, which are designed to organize multiple files as a single stream of bytes. responsible for organizing files and directories, and keeping track of which areas of the media belong to which file and which are not being used.
عمار عبد الكريم صاحب مبارك
AmmAr Abdualkareem sahib mobark
By Didar Hussain
Bacha Khan University Charsadda
This presentation will cover the idea of a file system. It contains much and more information i.e. different types of file systems like fat-16, fat-32, NTFS, Reiser file, journaling file, etc...
This is a self made slide covering topics related to storage systems available in the market with certain information of file systems to understand the fundamentals.
There are also some information is available related to how the whole stuff works.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
How libraries can support authors with open access requirements for UKRI fund...
File system Os
1.
2. Introduction to File Systems
All file systems consist of structures necessary for storing
and managing data. These structures typically include
an operating system boot record, directories, and files.
Functions of a File System:
Tracking allocated and free space
Maintaining directories and file names
Tracking where each file is physically stored on the
disk
3. Definition: Computers use particular kinds of file systems
to store and organize data on media, such as a hard drive,
the CDs, DVDs, and BDs in an optical drive or on a flash
drive. Any place that a PC stores data is employing the use
of some type of file system. A file system can be thought of
as an index or database containing the physical location of
every piece of data on a hard drive.
A file system is setup on a drive during a format. See How
To Format a Hard Drive for more information.
4. Types of File Systems
FAT File System
NTFS File System
Disk file systems
Flash file systems
Tape file systems
Database file systems
Transactional file systems
Network file systems
work file systems
Shared disk file systems
Special file systems
Device file systems
5. FAT File System
FAT12 - The initial version of the FAT file system, FAT12 was introduced
in 1977, even before MS-DOS, and was the primary file system for
Microsoft operating systems up to MS-DOS 4.0. FAT12 supports drive
sizes up to 32MB.
FAT16 - The second implementation of FAT was FAT16, introduced in
1988. FAT16 was the primary file system for MS-DOS 4.0 up to
Windows 95. FAT16 supports drive sizes up to 2GB.
FAT32 - FAT32 is the latest version of the FAT file system. It was
introduced in 1996 for Windows 95 OSR2 users and was the primary
file system for consumer Windows versions through Windows ME.
FAT32 supports drive sizes up to 8TB.
6. NTFS File System
Definition: New Technology File System (NTFS) is a file
system that was introduced by Microsoft in 1993 with
Windows NT 3.1. NTFS supports hard drive sizes up to
256TB. NTFS is the primary file system used in Microsoft's
Windows 7, Windows Vista, Windows XP, Windows 2000
and Windows NT operating systems. The Windows Server
line of operating systems also primarily use NTFS.
The File Allocation Table (FAT) file system was the primary
file system in Microsoft's older operating systems but it is
still supported today along with NTFS.
7. Disk file systems
A disk file system takes advantages of the ability of disk storage media
to randomly address data in a short amount of time. Additional
considerations include the speed of accessing data following that
initially requested and the anticipation that the following data may also
be requested. This permits multiple users (or processes) access to
various data on the disk without regard to the sequential location of
the data. Examples include FAT
(FAT12, FAT16, FAT32), exFAT, NTFS, HFS and
HFS+, HPFS, UFS, ext2, ext3, ext4, XFS, btrfs, ISO 9660, Files11, Veritas File System, VMFS, ZFS, ReiserFS and UDF. Some disk file
systems are journaling file systems or versioning file systems.
Optical discs
ISO 9660 and Universal Disk Format (UDF) are two common formats
that target Compact Discs, DVDs and Blu-ray discs. Mount Rainier is
an extension to UDF supported by Linux 2.6 series and Windows Vista
that facilitates rewriting to DVDs.
8. Flash file system
A flash file system considers the special abilities,
performance and restrictions of flash memory devices.
Frequently a disk file system can use a flash memory
device as the underlying storage media but it is much
better to use a file system specifically designed for a
flash device.
9. Tape file systems
A tape file system is a file system and tape format designed to
store files on tape in a self-describing form. Magnetic tapes are
sequential storage media with significantly longer random data
access times than disks, posing challenges to the creation and
efficient management of a general-purpose file system.
In a disk file system there is typically a master file directory, and
a map of used and free data regions. Any file
additions, changes, or removals require updating the directory
and the used/free maps. Random access to data regions is
measured in milliseconds so this system works well for disks.
Tape requires linear motion to wind and unwind potentially very
long reels of media. This tape motion may take several seconds
to several minutes to move the read/write head from one end of
the tape to the other.
10. Database file systems
Another concept for file management is the idea of a
database-based file system. Instead of, or in addition
to, hierarchical structured management, files are
identified by their characteristics, like type of file,
topic, author, or similar rich metadata.
11. Network file systems
A network file system is a file system that acts as a
client for a remote file access protocol, providing
access to files on a server. Examples of network file
systems include clients for the NFS, AFS, SMB
protocols, and file-system-like clients for FTP and
WebDAV.
12. Shared disk file systems
A shared disk file system is one in which a number of
machines (usually servers) all have access to the same
external disk subsystem (usually a SAN). The file
system arbitrates access to that subsystem, preventing
write collisions. Examples include GFS2 from Red Hat,
GPFS from IBM, SFS from DataPlow, CXFS from SGI
and StorNext from Quantum Corporation.
13. Special file systems
A special file system presents non-file elements of an
operating system as files so they can be acted on using
file system APIs. This is most commonly done in Unixlike operating systems, but devices are given file names
in some non-Unix-like operating systems as well.
14. Device file systems
A device file system represents I/O devices and
pseudo-devices as files, called device files. Examples in
Unix-like systems include devfs and, in Linux 2.6
systems, udev. In non-Unix-like systems, such as
TOPS-10 and other operating systems influenced by
it, where the full filename or pathname of a file can
include a device prefix, devices other than those
containing file systems are referred to by a device
prefix specifying the device, without anything
following it.
15. Flat file systems
In a flat file system, there are no subdirectories.
When floppy disk media was first available this type of file
system was adequate due to the relatively small amount of
data space available. CP/M machines featured a flat file
system, where files could be assigned to one of 16 user
areas and generic file operations narrowed to work on one
instead of defaulting to work on all of them. These user
areas were no more than special attributes associated with
the files, that is, it was not necessary to define specific
quota for each of these areas and files could be added to
groups for as long as there was still free storage space on
the disk..
16. Aspects of file systems
Space management
File systems allocate space in a granular
manner, usually multiple physical units on the device.
The file system is responsible for organizing files and
directories, and keeping track of which areas of the
media belong to which file and which are not being
used. For example, in Apple DOS of the early
1980s, 256-byte sectors on 140 kilobyte floppy disk
used a track/sector map.
17. Filenames
A filename (or file name) is used to
identify a storage location in the file system.
Most file systems have restrictions on the
length of filenames. In some file systems,
filenames are not case sensitive (i.e.,
filenames such as FOO and foo refer to the
same file); in others, filenames are case
sensitive (i.e., the names FOO and foo refer
to two separate files).
18. Directories
File systems typically have directories (also called folders)
which allow the user to group files into separate collections. This
may be implemented by associating the file name with an index
in a table of contents or an inode in a Unix-like file system.
Directory structures may be flat (i.e. linear), or allow hierarchies
where directories may contain subdirectories. The first file
system to support arbitrary hierarchies of directories was used in
the Multics operating system. The native file systems of Unix-like
systems also support arbitrary directory hierarchies, as do, for
example, Apple's Hierarchical File System, and its successor
HFS+ in classic Mac OS (HFS+ is still used in Mac OS X), the
FAT file system in MS-DOS 2.0 and later and Microsoft
Windows, the NTFS file system in the Windows NT family of
operating systems, and the ODS-2 (On-Disk Structure-2) and
higher levels of the Files-11 file system in OpenVMS.
19. Metadata
Other bookkeeping information is typically associated with
each file within a file system. The length of the data
contained in a file may be stored as the number of blocks
allocated for the file or as a byte count. The time that the
file was last modified may be stored as the file's timestamp.
File systems might store the file creation time, the time it
was last accessed, the time the file's metadata was changed,
or the time the file was last backed up. Other information
can include the file's device type (e.g. block, character,
socket, subdirectory, etc.), its owner user ID and group ID,
its access permissions and other file attributes (e.g.
whether the file is read-only, executable, etc.).
21. The Second Extended File system was devised (by Rémy Card) as an extensible
and powerful file system for Linux. It is also the most successful file system so
far in the Linux community and is the basis for all of the currently shipping
Linux distributions.
The EXT2 file system, like a lot of the file systems, is built on the premise that
the data held in files is kept in data blocks. These data blocks are all of the
same length and, although that length can vary between different EXT2 file
systems the block size of a particular EXT2 file system is set when it is created
(using mke2fs). Every file's size is rounded up to an integral number of blocks.
If the block size is 1024 bytes, then a file of 1025 bytes will occupy two 1024 byte
blocks. Unfortunately this means that on average you waste half a block per
file. Usually in computing you trade off CPU usage for memory and disk space
utilisation. In this case Linux, along with most operating systems, trades off a
relatively inefficient disk usage in order to reduce the workload on the CPU.
Not all of the blocks in the file system hold data, some must be used to contain
the information that describes the structure of the file system. EXT2 defines
the file system topology by describing each file in the system with an inode
data structure. An inode describes which blocks the data within a file occupies
as well as the access rights of the file, the file's modification times and the type
of the file. Every file in the EXT2 file system is described by a single inode and
each inode has a single unique number identifying it. The inodes for the file
system are all kept together in inode tables. EXT2 directories are simply special
files (themselves described by inodes) which contain pointers to the inodes of
their directory entries.
.
23. In the EXT2 file system, the inode is the basic building block; every file and
directory in the file system is described by one and only one inode. The EXT2
inodes for each Block Group are kept in the inode table together with a bitmap
that allows the system to keep track of allocated and unallocated inodes.
Figure 9.2 shows the format of an EXT2 inode, amongst other information, it
contains the following fields:
mode This holds two pieces of information; what this inode describes and the
permissions that users have to it. For EXT2, an inode can describe one of
file, directory, symbolic link, block device, character device or FIFO. Owner
Information The user and group identifiers of the owners of this file or
directory. This allows the file system to correctly allow the right sort of
accesses, Size The size of the file in bytes, Timestamps The time that the
inode was created and the last time that it was modified, Datablocks Pointers
to the blocks that contain the data that this inode is describing. The first twelve
are pointers to the physical blocks containing the data described by this inode
and the last three pointers contain more and more levels of indirection.
24. The EXT2 Superblock
The Superblock contains a description of the basic size and shape of
this file system. The information within it allows the file system
manager to use and maintain the file system. Usually only the
Superblock in Block Group 0 is read when the file system is mounted
but each Block Group contains a duplicate copy in case of file system
corruption. Amongst other information it holds the:
Magic Number This allows the mounting software to check that this is
indeed the Superblock for an EXT2 file system. For the current version
of EXT2 this is 0xEF53. Revision Level The major and minor revision
levels allow the mounting code to determine whether or not this file
system supports features that are only available in particular revisions
of the file system. There are also feature compatibility fields which help
the mounting code to determine which new features can safely be used
on this file system, Mount Count and Maximum Mount Count
Together these allow the system to determine if the file system should
be fully checked.
25. Conclusion
This paper discusses how the Modify-on-Access file system efficiently
extends the capabilities of conventional file systems. It demonstrates
how an active file system can simplify both applications and system
usage by performing computations on behalf of processes.
Furthermore, the paper describes the implementation of the MonA file
system and the export transformation. Section 5 shows that the
overhead of a kernel-resident transformation is very small and that
transforming data inline provides performance benefits. Furthermore, it
shows that the export transformation provides user extensibility.
The MonA file system is the first component of a suite of system
software designed for a collaborative memory system in which
intelligent peripheral devices collaborate with a host processor to
accomplish tasks. Current projects include a MonA virtual memory
system and a MonA peripheral device. These implementations are
similar to the Active Page and Active Disk simulations described in
related work.