¶ Introduction to Operating Systems
And welcome to Technology Tap . I'm Professor Jay Rod . In this episode we're going to talk about Operating Systems . Let's get to it , alright , welcome everyone .
For those of you who don't know me first time listening to Technology Tap , my name is Professor Jay Rod , that's J-R-O-D and I'm Professor of Cyber Security and the reason for this podcast is to help my students pass there , or any student out there pass their CompTIA A plus , network plus and security plus .
And you could not only find me on this podcast but you could also find me on TikTok . I'm at Professor Jay Rod , that's J-R-O-D , and there I do question and answers , quick one , two minute question and answer sessions .
I'll do a quick like definitions and stuff that's general for you to learn for the CompTIA exam , but it's like one or two minutes , three minutes the most burst . You don't want to get too many minutes on TikTok . People get bored , but I'm trying to get a thousand likes .
If I go and get a thousand likes I'll have the ability to go live and you know I can answer questions that you guys have about CompTIA , anything else . So make sure you look for me on TikTok at Professor Jay Rod . Alright , so today we are doing Operating Systems , so let's take a look .
So it's different functions of a core function of the operating systems , and there's several . We might have to do this in different stages . It might not be just , it just might be a part two , depending how long you know we last .
Usually for those of you who are new usually I try to make the podcast between 27 to half an hour , not not too much longer than that . So if I go past 28 minutes , 29 minutes , I'll stop and I can do a part two of core functions of Operating Systems , alright . So let's look at the first function , which is process management .
And then process management is a fundamental aspect of operating systems . That involves the creation , scheduling , execution and termination of processes , and here's an overview . One is process creation , which includes program execution processes . Processes are instance , instances of executing programs .
When a program is executed , the operating system creates a new process to execute the program's instructions . Also fork operation . In Unix , like operating systems , the fork system call is used to create a new process which is a copy of the parent process . The child process can then execute a different program using the exec system call .
Next is process state we have new . The process is being created ready . The process is ready to execute and is waiting for the CPU and then running . The process is currently being executed by the CPU , blocked or waiting . The process is waiting for an event to occur , such as user input or I O operations , and then the last is terminated .
The process is finished . Execution . Next we move on to process scheduling . When you scheduling an algorithm , the operating system scheduler determines which process to execute next on the ski on the CPU . Scheduling algorithms include first come , first serve , shortest job , next round Robin , priority scheduling and multi level to scheduling . Next is context switching .
When the scheduler switches from executing one process to another , a contact switch occurs where the state of the current process is saved and the state of the next process is restored . Process synchronization and communication Synchronization process may need to synchronize their execution to access shared resources or avoid race conditions .
Synchronization mechanisms like semi forms and monitors ensure mutual exclusive access to shared resources . Inter process communication processes may communicate and exchange data with each other using IPC mechanisms or inter process communication mechanisms such as pipes , message queues , shared memory and sockets . Process termination First we start with normal termination .
A process terminates after completing its execution on a specifically calls the exit system . Call Abnormal termination A process may terminate abnormally due to errors , exceptions or signals . And then we have cleanup . When a process terminates , the operating system releases allocated resources , closes , open files , the allocates memory to prevent resource leaks .
Next we go to process control block . The CB , the PCB structure . Each process is presented is represented by process control block in the operating system . The process control block contains information about the process sees , including is processing ID , state program counter , cpu registers , memory allocation and scheduling information . Pid is processing IDs .
If you look at task manager from the command line , you see the PID numbers for for different numbers that you have open . So let's say you have no pad open and you do task manager , you see the the PID number for no pad .
Process management operations the operating system performs various process management operations , including process creation , scheduling , contact switching , synchronization and termination based on the information stored in the PCB .
Process management is a critical component of modern day operating systems , enabling efficient multitasking , resources allocation and coordination of current activities in computing environment . Operating systems use sophisticated and sophisticated process management techniques to maximize CPU utilization , improve system responsiveness and ensure reliable execution of software applications .
Next we are going to memory management . Memory management is a crucial aspect of operating systems that involves the allocation , the allocation and organization of memory resources in the computer systems . Let's take a look at an overview . First we look at memory hierarchical hierarchy .
First we start with registers , the smallest and fastest type of memory located within the CPU used to store data and instructions being processed . Cache high speed memory located between the CPU and the main memory , used to temporary store frequently access data and instructions .
Main memory , which is RAM volatile memory used to store instructions and data during execution . You have secondary storage , non volatile storage , like what hard drives and solid state drives used for long term storage . We have next main memory management unit . It's responsible for translating logical address generated by the CPU into physical address in main memory .
Memory management unit perform address translation , memory protection and memory segmentation or paging . Next we have memory allocation , both static and dynamic . Static allocation is when memory is allocated to programs at compiled time and remains fixed throughout the program's execution . Dynamic memory is memory allocated and deallocated during a program execution as needed .
Next we have memory protection . Operating systems enforce memory protection mechanism to prevent unauthorized access to memory regions . Read only read , write and execute . Permissions are assigned to memory pages to control access by processes . Memory protection helps prevent buffer overflows , stack smashing and other security vulnerabilities . Next we have virtual memory .
Virtual memory allows programs to use more memory than physically available by using combination of RAM and secondary storage , as memory pages are swapped between RAM and disk storage to accommodate the program's memory requirements . Virtual memory enables effective memory utilization , multitasking and memory sharing among processes , and that's very .
If you've never done that , it's pretty cool to see that in action . And you can always increase your virtual memory on your computer . That's very easy to do . Next is memory paging . Paging is a memory management scheme that divides physical memory into fixed size blocks called pages .
Virtual memory address are mapped to physical memory address using page tables operated by and maintained by the operating system . Memory reduce memory fragmentation and enables efficient memory allocation and management . Then we have memory fragmentation .
Fragmentation occurs when memory is allocated and deallocated in a way that leaves unused memory blocks scattered throughout the address space . Fragmentation can lead to inefficient memory usage and reduced system performance . Precinct , like compaction and memory pooling , are used to reduce fragmentation and improve memory utilization .
Memory swapping Memory swapping involves moving inactive or less frequent use memory pages from RAM to disk storage to free up physical memory for active process . Swapping is performed by the operating system's memory manager , based on predefined swapping algorithms and memory usage patterns .
Memory management is critical for optimizing system performance , ensuring reliable programming execution and maintaining system stability . In modern operating systems , operating systems use a combination of memory management techniques to efficiently allocate , protect and utilize system memory resources across diverse computing environments and workloads .
File system management is the next one . File system management is a crucial component of operating systems that facilitates the organization , storage , retrieval and manipulation of files and directories . Here's an overview . First we start with file system concepts . Files are logical units of data stored on storage devices .
They contain user data , programs , configurations and other information . Next we have directories . Directories or folders Are containers used to organize and group related files and other directories within a hierarchical structure . Paths are unique identifiers that specify the location of files and directories within the file system hierarchy , like see users downloads .
Right , that's a path . File attributes . A file system store beta data associated with files , including file name , size , creation , date , modification , date , permission and ownership . File system types . It's next disk based file system .
Disk based file systems like NTFS for Windows , ex4 for Linux and HFS Plus for Mac OS are optimized for storing and accessing files on the hard disk drives and solid state drives , you have your network file systems . Network file systems enable file sharing and access over the network .
Files include NFS for Unix like systems , and SMB , which is small message block , and CIFS for Windows system , and you need that small message block . You need for more than just files . You could use it for printing also Distributed file systems .
Distributed file systems like how do distributed file systems and Google file systems distribute and manage file storage across multiple servers and distributed computing environment . Next we have file operations , file creation and deletion . Operating systems provide API and system calls for creating , deleting and managing files .
Examples includes open , close , create unlinked system calls . And that's where , like Unix , if some of you are not familiar with those File writing and reading file system support reading , write operations for reading data from files and writing data to files using systems calls like read and write , and then files seeking .
File seeking operations allow users to navigate within the files and move the file pointed to specific position using functions like seek , find , search , right File system organization . File allocation table , or FAT , is a simple file system structure used in older Windows systems for organizing files and directories .
They use FAT and FAT32 on USBs Master file table , mft . Ntfs uses master file table to store metadata and file systems . Metadata structures Inno's Unix , like file system use . X4 uses index nodes or in nodes to represent files and directories and store metadata associated with them .
And then you have file system features journaling file systems like X4 and NTFS use journaling to record file systems transactions , ensuring data consistency and reliability in the event of a system crash or power failures . File compression some file systems support file compression techniques to reduce storage space usage and improve file transfer efficiency .
Encryption file system encryption features like BitLocker for Windows and FileVolve for Mac OS . Encrypt file content to protect sensitive data from unauthorized access . And then access control list allows administrator to define granular access permission for files and directories , specifically which users or groups have rewrite or execute permissions .
File system maintenance you have file system check it's a utility that scans and repair file system errors , inconsistencies and corruption to maintain data integrity and prevent data loss . Defragmentation it's a utility that optimized this performance by rearranging fragmented files and consolidating free space on storage drives .
Stand by sleep to conserve energy and extend battery power in mobile devices and laptop . Power management policies operating system implement power management policies to control device power states dynamically based on a system , workload , user activity and power source conditions .
Device monitoring and maintenance device monitoring operating systems monitor device status , perform metrics and error conditions to detect hardware failures , driver issues and resource conflicts . Device configurations and diagnostics systems . Utilities and administrator tools allow users to configure device settings , diagnose hardware problems and perform maintenance task .
Device security access control operating systems enforce access control policies to restrict access to sensitive devices and device resources based on user privileges and permission . Device isolation , virtualization technologies and containerization techniques provide mechanisms to isolate and sandbox device access for security and reliability purposes .
Device hot plugging and removal hot plugging allow users to connect and disconnect devices from the system while it's running without requiring system reboot and hot swapping . So system support hot swapping device where device can be replaced or upgraded without interrupting system operations .
Device management plays a crucial role in ensuring efficient and reliable operations of hardware devices within the operating system .
By abstracting hardware complexities , providing standard standardize interfaces and implementing robust management and control mechanism , operating systems enables seamless integration and interaction between software application and the diverse range of hardware peripherals and components .
First we have security and access control , which are critical aspects of operating systems , ensuring that resources are protected and only authorized users or processes can access . Here's an overview of security and access control mechanisms in operating systems . First one is user authentication . You have your login credentials .
Operating systems requires users to authenticate themselves using login credentials such as username , password , pins or biometric data , fingerprint , facial recognition of the like , multi-factor authentication , which is the big thing now , as an extra layer of security , by requiring users to provide multiple forms of identification , such as password and one time code sent to
their mobile device . So people talk about multi-factor authentication at my students . How long do you think multi-factor authentication has been around ? And some people say like , oh , two years . Or some people say five years , some people say 10 years . It's actually been around for longer than that . It's actually been around for like 40 years , I think .
Because if you look at one thing , that's multi-factor , that's been around for years , and I'm going to tell you you're going to be like oh yeah , you're right . Taking money out of the ATM machine , that's multi-factor . You need a card , which is something that you have , and you need the pin , which is something that you know . That's multi-factor .
Right , that's not the multi-factor , like you know now , where they send a code to your phone one time code but that is multi-factor . Taking money out of the ATM is a multi-factor that you're doing so . It's been around for a long time . All right Access control models
¶ Operating System Security Mechanisms and Certifications
. You have your discretionary access control , or DAC . Allows users to control access to their own resources by setting permissions on files and directories . Permissions include read , write and execute privileges for the owner group and others . You have mandatory access control , or MAC . Enforces access control policies based on a system-wide rules set by administrators .
Users cannot override MAC rules , which are typically based on security labels or classifications like secret , top secret , that sort . Then you have role ACLs access control lists . Acls are a list of permissions attached to files and directories , specifically which users or groups have specific access rights read , write , execute .
Extended ACLs allow finder granular control by specifying access permissions for different user class , owner groups and others and applying additional rules based on user attributes or roles . Then you have rule-based access control , which assigns permissions to users based on their roles within their organizations .
Users are assigned roles and permissions are associated with those roles . This simplifies administration and ensures consistent access control across the organization . If they have somebody who's special , then that messes up everything . And if you know , you know Security policies and enforcement Security policies .
Operating systems enforce security policies to govern user behavior , resource access and system configuration . Policies define rules for password complexity , account lockout , file passwords , file permissions and network access .
Security Audit Security Audit Mechanism track users activity , system events and access attempts to detect security breaches , policy violations and suspicious behavior . Encryption and data protection you have file encryption . Operating systems offer encryption features to protect sensitive data stored on disk .
Encryption algorithms like AES advanced encryption standards encrypt files and directories to prevent unauthorized access . Disencryption full disencryption solutions like BitLocker for Windows and Favol for macOS encrypt an entire disk volume to safeguard data at rest .
Firewall and network security Firewall operating system may include a built-in firewall software to monitor and filter network traffic , blocking unauthorized access attempt and malicious connections . Network security Operating systems support network security protocols like IPsec and SSLTLS to encrypt network communications to ensure data confidentiality and integrity .
Software updates and patch management Software updates operating system vendors release security patches and software updates to address vulnerabilities , bugs and security flaws . Regular updates help mitigate security risk and protect against known threats . Then you have patch management .
Patch management tools automate the process of deploying software updates and patches across distributed systems , ensuring that systems remain up to date and secure . By implementing robust security and access control mechanism , operating systems help safeguard sensitive data , prevent unauthorized access and mitigate security risk in computing environments .
These mechanisms ensure that authorized users and processes can access resources , protecting confidentiality , integrity and availability of information assets . I'm trying to get into the granular of the operating system so that people think about operating systems and they just take up windows and what it can and cannot do .
They need to look at the granular of what windows , mac , linux , unix , what they all do , and this is what we're trying to do here at TechnologyTap . So just a few housekeeping tips . I'm still doing TechnologyTap Premium for those of you who want to join . It's an extra service , $5 a month .
Not looking to get rich off you guys , but you know there are expenses to doing a podcast . I want to be able to do giveaways . I want to . I gave away . Actually he did a nice thing . I have a winner who won the network plus . He won it over the summer network plus certification voucher . He actually wants me to give it away .
I don't know how I'm going to do that yet , but he told me that I can give it away to anybody who wants because he recently got his security plus . He's not really interested in network plus , but shout out to him my winner who won over the summer . And if anybody's interested you know what , let's do this .
If anybody's interested in getting a free network plus voucher , write me an email at Professor J Rod as JROD , and tell me why I should pick you . Why should pick you for this ? You know network voucher , that that time is in the Thomas Otomas one and he wants to give it out .
So if you think that's you , email me , professor J rod , at gmailcom and tell me why you should win . Right , you should put on the subject why should I win , you know ? Or network certification . Yeah , put network certification on the on the subject line .
That way I make sure that it's not spamming and throw it out and then give me a compelling reason why you think you should get it . Now , if you've never studied for the , for the network plus exam , don't send me an email , right , because you know if you haven't studied for it .
But if you study for it and you ready to take network plus and the barrier is this the . You know the . You know you don't have the money for the certification , email me , right , you know . I find that that's one of the , the biggest thing that I see . That's a very big barrier for a lot of my students .
He said they take the course or they study and they tell me that they ready , but they can't afford to buy a voucher Because these vouchers are . They're not cheap , they're expensive .
So part of the reason why I do this podcast is in the tick tock now is I'm hoping that somebody like CompTIA notices me and then not that they , not that I want to get sponsored for money , but I would like to get sponsored to give away , you know , comptia vouchers , because I think that that is the number one obstacle for people Getting their certification .
Believe me , guys , I teach comp TIA a plus all the time , like all the time right , and and I know that that's the you know I'll get , let's say , 20 students to take the comp TIA and out of the 20 , there may be 12 who I think Already to take the exam and out of those 12 , maybe one or two of them will actually take it because you know they want .
They want to make sure that they're ready and they don't want to spend their money to take the exam and then fail Right . They want to make sure that they 100% ready and Even if I tell them , look , I think you're ready , they still won't take it because they don't want to fail , because they don't want to spend the money .
It's a lot , it's a lot for them . You know , a plus is two exams , like two hundred and sixty four dollars , that's five , it's over five hundred bucks .
So , you know , if I could get , you know , if somebody from comp TIA ever listens to this Right and and they want to sponsor me and and you know , say , hey , we'll give you , you know , a voucher every , I don't know , once a month or once every other month , I'll be glad to give it away .
I'm not , I'm not here to make , you know , to be a millionaire , but you know , I'm here to help people who want to get the certifications , because , take it for me . I know the computers change your life . I mean , I know that IT , like any job , right , you got to be passionate about it , but I know it changed my life , it could change your life .
You know , moving over to academia of IT definitely changed my , my life . You know , you got willing . I'm only a few , a few weeks away from From being a doctor Rodriguez instead of professor Rodriguez , but that's the story for another day . Guys , I'll let you know if and when that ever . You know if and when that happens .
So , but you know I this is why I do this right . I want , I want people out there too to get certified and and become very successful . And you know , it doesn't matter that you end up making more money than me . That's my big joke that I tell my students , you know , and I won't be mad if you make more money than me .
Now you buy me a steak , you know when you , when you . You know , I have a student who works at a and at a famous beer distributor or beer maker , and he still has me a case of beer because he says they Like they . There's cases like when you leave the office , there's like cases right there . You can just Pick it up and and take it with you .
So he still owes me a case . I won't say which one , but he knows . He knows what I'm talking about . I saw him recently , so he knows . But this is why I do it , guys . I do it , you know , for you . So you know . That's why , when you see like , oh wait , he hasn't come out with an episode For a while .
It's not that I'm slacking , yeah , I'm doing other things , doing my dissertation now . So that took up a lot of my time but you know I'm as long as I'm around .
I'm gonna still try to do this podcast and I hope and pray that somebody recognizes me and recognize what I'm trying to do here and , you know , believes in this , what we're doing , and agrees to sponsor me . But Anyway , next time we'll do part two on operating systems . I'm looking at my notes .
It's a lot , so might either do part two or maybe you're in a part three on operating systems . But until next time We'll see you . This has been a production of Little Chachal . Productions are by Sarah , music by Job Kim . If you like to reach me , you can reach me at professorjrodjrod at gmailcom .
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