Files & File Systems: Crash Course Computer Science #20

Поділитися
Вставка
  • Опубліковано 24 гру 2024

КОМЕНТАРІ • 414

  • @Supermunch2000
    @Supermunch2000 7 років тому +505

    This crash course is one of the most delightful things to ever appear on the internet.
    Thank you Carrie Anne, Stan and everybody else involved.

  • @imaytag
    @imaytag 7 років тому +297

    Every time I watch one of these videos I always imagine going back in time and showing it to an early computer scientist and seeing their reaction to how far we've come.

    • @imaytag
      @imaytag 7 років тому +14

      Heh, yeah. But I meant going back to a time when the technology was still developing. And seeing their reaction for those times when Carrie Anne casually references the capabilities of modern computers.

    • @sauravligal5809
      @sauravligal5809 5 років тому +1

      evolution of computer is fast...

    • @nosuchthing8
      @nosuchthing8 5 років тому +4

      Yeah, but they would be shocked we still don't have human level ai.

  • @Phantom-nb5li
    @Phantom-nb5li 5 років тому +45

    It's great that the presenter doesn't shy away from "advanced" topics (in any of the videos in this course) - that provides something for every "level" (beginner / intermediate / advanced) of viewer. Great job with these videos !

  • @23trekkie
    @23trekkie 7 років тому +140

    Defragmentation was fun to watch... If you had angelic patience and nothing better to do.
    Before defragmentation - 25% fragmentation.
    12 hours later - 24% fragmentation.

  • @videoinformer
    @videoinformer 4 роки тому +5

    I often speed up informative UA-cam videos by 25%.
    This extremely good presenter obviates the need, and speaks just about 25% faster than "normal" with perfect articulation and fluidity that makes it easy to take in what she is saying without any flaws to distract.
    A playback speed of 80% would "undo" a 25% increase over "normal". (1/1.25=0.8).
    If you slow this video to 75% (the closest to 80% that's available), the presenter sounds like she's speaking a little more slowly than normal, so I'd say, yes, she's naturally speaking about 125% of normal rate.
    And, very well done!

  • @PrivateYouTubeE
    @PrivateYouTubeE 4 роки тому +25

    After so many years, I finally know defragmentation means and what it does. Thank you so much.

  • @WiseWik
    @WiseWik 7 років тому +604

    Only 90's kids remember how fun it was to watch defrag.

    • @hopeg97
      @hopeg97 7 років тому +24

      Pajaat Or 00's kids with passed-down legacy hardware. I remember watching Windows XP defrag. I think I also remember Windows 7 defragging, but it wasn't nearly as fun. (born '97, so anything before 2002 is lost to childhood amnesia)

    • @JimPlaysGames
      @JimPlaysGames 7 років тому +12

      You can always get third party defraggers with nice GUIs that show off the data juggling.

    • @huge_aubergine
      @huge_aubergine 7 років тому +27

      I wouldn't say it was fun. I was expecting my Windows to run smoothly after every defrag, but it never happened :(

    • @Lenmarrrk
      @Lenmarrrk 7 років тому +7

      I'm 00's kid, and I remeber that defrag^^

    • @IIGrayfoxII
      @IIGrayfoxII 7 років тому +13

      The Windows 9x defrag utility was the best, all those little blocks.
      XP just had the stupid bar which didnt tell you much
      Windows vista and newer got rid of the animations with the claim it improves performance.

  • @evanl5299
    @evanl5299 6 років тому +7

    I just read a full textbook chapter on this, but the way you described file systems made it so easy to understand!
    Thanks for this excellent, concise video. Great work!!

  • @vaibhavtripathi4951
    @vaibhavtripathi4951 5 років тому +3

    crash course has biggest impact on the world in recent decade. it changes the way we see UA-cam, technology and education. thanks to green brothers.

  • @dixztube
    @dixztube 2 роки тому +3

    This was pretty good! Read a couple chapters today in a Linux book covering storage partitions and file systems and this had some tidbits a fairly technical book left out.
    I’ve been developing for 5 years now and finally just now falling in love with computer science

  • @Agen7P
    @Agen7P 7 років тому +75

    We're now up 20 Layers of abstraction.

  • @somethingnew3338
    @somethingnew3338 Рік тому +1

    best explanation for file system. I saw around 10 videos till now. thanks and congrats

  • @sameerkumar1884
    @sameerkumar1884 4 роки тому +2

    This video is really informative for knowing nitty gritty about file system specially "Block Storage"... It can also be used to understand about newly evolved Object storage...

  • @djmontoro
    @djmontoro 7 років тому +4

    This is by far the Crash Course series from which I have learned more. Thanks, Excellent work!!!

  • @lorenz_codes
    @lorenz_codes 2 роки тому +6

    I feel like I struck gold with this series! Thanks for making these videos!

  • @tylerblackstock6452
    @tylerblackstock6452 7 років тому +8

    Love this whole series, you make it easy to understand the flow of technological advancement

  • @alexandercountry
    @alexandercountry 7 років тому +5

    Carrie you are my new spirit animal.

  • @noemiej.marquis732
    @noemiej.marquis732 7 років тому +640

    Just realised it's a bit ironic that these computer science courses are called "crash" course. ;)

    • @jakekimds
      @jakekimds 7 років тому +51

      Crash Course rocket science... coming soon!

    • @tanxyrogue847
      @tanxyrogue847 7 років тому +18

      coincidence isn't irony but that doesn't stop the phrase from being ironic

    • @bakedutah8411
      @bakedutah8411 7 років тому +1

      I wonder who first used "crash" to describe a computer getting into a fankle. It's such a common usage I'd never thought about it until you just mentioned it.

    • @AckzaTV
      @AckzaTV 7 років тому +2

      no its not ironic because Crash Course was not made just fpr computer science, this is all brand new subject, man after they have every subject on earth done there will be No need for school or teachers and thank god

    • @justluc8556
      @justluc8556 6 років тому

      😂

  • @thecentalist3160
    @thecentalist3160 7 років тому +5

    YAY two of my favorite series uploaded on the same day.

  • @biggerdoofus
    @biggerdoofus 7 років тому +2

    A bit of extra info about the making of custom file formats: since the data just needs to be in an order that the program using it can process, and that program is usually made by humans to at least some extent (though rarely entirely nowadays), it's also not uncommon to design new formats on top of text formats so that they'll be "human-readable". This is especially useful if you want users to be able to adjust data themselves, such as in the case of configuration files and simpler level editors for video games. That method also helps the data be easier to transfer across different computer architectures, which is why it's used in html and xml (formats used for websites and similar applications).

    • @Roxor128
      @Roxor128 7 років тому

      The downside, of course, is that text-based formats are rather space-inefficient and writing routines to read them isn't the simplest of tasks. Mainly because when it's human-readable, humans will edit it, and the mistakes they make are many and varied, requiring a lot of work on your part to figure out where they've gone wrong and come up with a suitable error message. Much like writing a compiler, actually. Most of the work there is making sure the file it's been fed is valid Foogol code (I hope nobody has made an actual language with that name because it's a good placeholder name).

  • @WoutiecomNL
    @WoutiecomNL 2 роки тому +5

    Wow, my first time watching a video from your channel. As I am interested in File Systems I came across this video. You, Carrie, can explain it very clearly and your animations and sounds are pleasing on the eye ;)

  • @therealquade
    @therealquade 7 років тому +3

    >Opens audio editor
    >renames a jpg as .wav
    >opens ".wav" in audio editor
    >adds effect
    >saves ".wav"
    >Renames to .jpg
    >Opens in hex editor
    >fixes metadeta that was lost/damaged
    >Opens image

  • @TYKUHN2
    @TYKUHN2 6 років тому +12

    I can understand the simplification, but it is important to remember that many programs running under Unix/Linux do not care about extension and furthermore EXT4, a common Linux filesystem, does not experience fragmentation.

    • @TYKUHN2
      @TYKUHN2 6 років тому +2

      Peterolen very few programs (at least that I work with) care about the extension

  • @MOHx32
    @MOHx32 7 років тому

    I can't.... Stop..... BINGE WATCHING!!! I feel the knowledge coursing through my grey matter, ALMOST TO LEVEL 9000! WHAAAH!!!!

  • @dowhile5948
    @dowhile5948 5 років тому +1

    you have worked hard to make these videos.These videos are the best about computer science.

  • @oslonorway547
    @oslonorway547 7 років тому +47

    I remember the first time a teacher told me to find a _file_ on a computer ..... I spent 5 embarrassing minutes looking for any icon that looked like a clipboard or spiral notebook. Later I found out that was the Calendar icon.

  • @Blaineworld
    @Blaineworld 7 років тому +1

    I like how these videos make use of the font Terminal. It's a really good pixel font, which it honestly has to be since it's used on the Command Prompt.

  • @vaibhavdeshmukh7900
    @vaibhavdeshmukh7900 5 років тому +9

    How I am so late to know about this amazing channel!!! I guess nowadays youtube is getting so much filled by shitty channels that awesome channels are getting missed!

  • @miklos.
    @miklos. 7 років тому +2

    Love the series so much!

  • @enricmm85
    @enricmm85 4 роки тому +5

    "Defragmentation [...] once upon a time it was really fun to watch."
    Indeed.
    RIP old Windows defrag tool 😢

  • @austina2002
    @austina2002 5 років тому +1

    I am glad to have found this series. Very informative. I will recommend to others!

  • @Revisiontecnica
    @Revisiontecnica 7 років тому +47

    WHEN WILL THERE BE "ANOTHER LEVEL OF ABSTRACTION" TSHIRTS?!!!!

  • @quitoxictv8307
    @quitoxictv8307 2 роки тому

    the fact this is free blows my mind

  • @borriskarlov8140
    @borriskarlov8140 5 років тому

    this series is SO empowering

  • @BBBuilds12
    @BBBuilds12 7 років тому +32

    Ext4 is the best!

    • @archlinuxrussian
      @archlinuxrussian 7 років тому +3

      Correctrix *xfs ;3 lol. I think we can all agree these three are better than HFS+ ;)

    • @eddiesantos7232
      @eddiesantos7232 7 років тому +2

      But... don't you like case-insensitive filenames, strange extended attribute storage, and a *special* version of Unicode denormalization applied to every filename? :p

    • @rydohg
      @rydohg 7 років тому +1

      archlinuxrussian Umm, actually FAT32 is the best file system

    • @hugosz283
      @hugosz283 7 років тому +6

      My 5GB files disagree :P

    • @markgriz
      @markgriz 7 років тому +8

      You kids get off my lawn. FAT12 forever!

  • @zakunknown9737
    @zakunknown9737 7 років тому +1

    TY Carrie Anne, love your series!!!

  • @Lucuskane
    @Lucuskane 7 років тому +2

    what a satisfying video, I love my file system

  • @tuseroni6085
    @tuseroni6085 7 років тому

    fun little aside about ascii:
    take the number of the letter you want to encode (count your alphabet, 1 for a 2 for b etc) then add 64 for uppercase or 96 for lowercase, and that's the number in ascii or utf8. if you are looking to do it in binary, and know how to count in binary, add 10 to the beginning of the number for uppercase and 11 for lowercase (or bitwise or 1000000 or 1100000. so for a you just take 00001 and add 11 to the beginning to get 1100001 for a lowercase a..you can go through your alphabet like this, 00001,00001,00010,00011,00100,00101,00110,00111,etc) if you know how to count in binary on your hands you can just count as you go through your alphabets and get the result in binary on your hand.

    • @RaymondHng
      @RaymondHng 7 років тому

      You cannot do that with EBCDIC encoding because of its not non-contiguous letter sequences.

    • @tuseroni6085
      @tuseroni6085 7 років тому

      why would you make an encoding scheme with non-contiguous letter sequences?

    • @RaymondHng
      @RaymondHng 7 років тому

      tuseroni
      Extended Binary Coded Decimal Interchange Code (EBCDIC) is an eight-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. EBCDIC descended from the code used with punched cards and the corresponding six bit binary-coded decimal code used with most of IBM's computer peripherals of the late 1950s and early 1960s. It descended from Hollerith encoding used on punch cards. The letters A through I consisted of a punch in the 12th row and a punch in the first through ninth row. The letters J through R consisted of a punch in the 11th row and a punch in the first through ninth row. The letters S through Z consisted of a punch in row zero and a punch in the second through ninth row.

    • @tuseroni6085
      @tuseroni6085 7 років тому

      that doesn't answer the question of WHY?

    • @RaymondHng
      @RaymondHng 7 років тому

      A punch card consisted of 80 columns with twelve possible punch rows. Hollerith encoding consisted of one hole punched for a number, two holes punched for an alphabetic character, and three holes for punctuation characters. Punching more holes in a column weakens the card causing it to jam in high-speed card readers. When IBM developed their Series/360 mainframes in the 1960s, ASCII encoding had not been created.

  • @LinhNguyen-bp9hd
    @LinhNguyen-bp9hd 4 роки тому

    that clears up a lot, cant believe I have just understood fragmentation after 20years using computer

  • @darylbangerter7171
    @darylbangerter7171 7 років тому +3

    Looking forward to Crash Course: Interpretive Dance :)

  • @ronsxx78
    @ronsxx78 5 років тому +1

    Crashcourse is better than my college professors

  • @TheAAMoy
    @TheAAMoy 7 років тому +16

    HALT and CATCH FIRE, I miss the good old days.

    • @justplainc
      @justplainc 7 років тому

      Tell me you also watch the show!

  • @kannanhassouna8789
    @kannanhassouna8789 4 роки тому

    i love this series
    so much

  • @sss2393
    @sss2393 4 роки тому

    Big fan of your teaching. Awesome as always, thanks a ton!

  • @bee5120
    @bee5120 7 років тому +48

    The best thing about SSD's? No defragmentation required.

    • @BertGrink
      @BertGrink 7 років тому +24

      Not only is it not required, but it would actually be detrimental to the "health" of the SSD, since each storage cell can only be written to a limited (albeit reasonably large) number of times.

    • @Nibbleminx
      @Nibbleminx 7 років тому +1

      미셜비 that only half the truth. ssds will preread/precache the next blocks just in case they are needed, defragmentation can have a performance benefit even on ssds

    • @andythepandaninja3859
      @andythepandaninja3859 7 років тому +4

      teleturbo Trying to defrag a SSD would do more harm than good as explained by Gert Brink Nielsen.

    • @Nibbleminx
      @Nibbleminx 7 років тому +1

      AndyThePandaNinja it depends how you defrag and what filesystem you use .

    • @NizarElZarif
      @NizarElZarif 7 років тому +7

      usually, SSDs have their own firmware and controller that knows what is the health of each block and where the data is best located. the controller along with the firmware handles defragment and file placement. this is much better than relying on your operating system since the firmware maintain optimal health and speed and reduce data corruption is best left to the manufacturer since each type of SSD uses different NAND types, and different controllers and different configuration.

  • @seanlee566
    @seanlee566 2 роки тому

    Love that the part about 'deleting a file' is the most replayed

  • @HH-zi2oj
    @HH-zi2oj 6 років тому +2

    I learned a lot from Carrie Anne than my professors xD Thank you Crash Course! :D

  • @utkarshupadhyay74
    @utkarshupadhyay74 5 років тому +1

    Exactly what I was looking for.Thanks for spreading knowledge.

  • @AuburnKamstra
    @AuburnKamstra Рік тому +1

    this episode makes me desperately want a crash course linux series (sincerely, a braindead Ubuntu user)

  • @michaniki1684
    @michaniki1684 4 роки тому +1

    i always somehow end up coming back to this computer science crash course XD

  • @addison1977
    @addison1977 4 роки тому

    This series is so good

  • @jayvl09
    @jayvl09 7 років тому

    I think it might be worth mentioning a single file can have multiple paths. Also that hierarchical ordering mechanisms like folders aren't the only solution. We might see non-hierarchical tag-based filesystems in the future.

  • @androidaleccc
    @androidaleccc 6 років тому

    I just wanted to say you are awesome, you do a really good job.

  • @avi12
    @avi12 6 років тому

    I'm fascinated by how you explain about metadata and data! So cool!

  • @ishbanyadav
    @ishbanyadav 7 років тому +35

    Its really great that you are talking about things that relate more to everyone.

    • @abs_nobody
      @abs_nobody 7 років тому +15

      well that's not the purpose of this series tho

    • @madLphnt
      @madLphnt 7 років тому +5

      hahaha, the title is computer science not physiology

  • @Joetechlincolns
    @Joetechlincolns 7 років тому +1

    I remember loading programs through DOS on start up. Changing command prompts etc. Now, all I ever deal with is testman errors using FORD scan tool software. No clue with all this new stuff.

  • @ErikDaGreat
    @ErikDaGreat 6 років тому +1

    i remember my father doing defragmentation on windows xp. it was about 7-8 years ago. i remember it was so colourful

  • @chrisshyi8999
    @chrisshyi8999 7 років тому

    Very educational, keep the great content coming!

  • @bayroncabrera7566
    @bayroncabrera7566 2 роки тому

    This is so amazing, i cannot thank you enough for such a wornderful job.

  • @Blockietalkie
    @Blockietalkie 7 років тому +1

    File systems are the best!

  • @mohamedabdelaal8582
    @mohamedabdelaal8582 6 років тому

    this is sooo well put together! thank you!!!!

  • @cdg03
    @cdg03 7 років тому

    Fantastic, logical, well structured explanation. Thank you so much.

  • @endlessbattle9122
    @endlessbattle9122 5 місяців тому

    Thanks for the knowledge ❤

  • @ler9251
    @ler9251 5 років тому +1

    Number of abstraction level > storage space in my head👍

  • @rampage241
    @rampage241 7 років тому

    awesome as always

  • @rjwhite4424
    @rjwhite4424 7 років тому +1

    please continue to make these videos. They are awesome to computer nerds like me.

  • @guyr989
    @guyr989 6 років тому

    This explains so much!! wish I could liked it more times

  • @davidepaula
    @davidepaula 7 років тому +46

    I absolutely love this series. Thank you for putting this together. Do you mind sharing that Putin.jpg [9:45] file that was inside the WORLD_HISTORY directory? Oh, and tell Stans that saving passwords inside a .txt file is not a very good idea. ;-) .
    I know you have already done 20 of these in Computer Science, but please keep them coming. Thank you.

    • @UnpopularName
      @UnpopularName 7 років тому +5

      you were thinking Putin.jpg? i was wondering what Skoodilypoop_Animation.mp4 was...

    • @mohammadabdullahansari6314
      @mohammadabdullahansari6314 6 років тому +1

      You can find that in World History.

  • @ulysses_grant
    @ulysses_grant 5 років тому +2

    Thank you, I finally figured out what is metadata, and why it has this f...antastic name.

  • @chaosof99
    @chaosof99 7 років тому +1

    I would have loved to see a little bit mentioned about file compression here, or maybe this is in an upcoming episode.

    • @hciprof
      @hciprof 7 років тому

      The force is strong with you. It's episode 21 :)

  • @TriaMaxwell
    @TriaMaxwell 7 років тому +4

    Does the Mongol Warrior file have a bug where it benefits from an "exception"? Or is that a feature?

  • @DavidsKanal
    @DavidsKanal 7 років тому

    This was so informative, loved it. Thanks so much!

  • @brocksprogramming
    @brocksprogramming 7 років тому

    Way to go Carrie Anne. Great video!

  • @almuhanadahmedsaidalhashmi4696
    @almuhanadahmedsaidalhashmi4696 4 роки тому

    I love this episode ☝️❤️❤️

  • @amankumarkashyap400
    @amankumarkashyap400 5 років тому +1

    I have a doubt @ 8:00 it has been said that we actually don't remove the data we just remove the record from the directory file.And since we are only
    storing the block number , How do we know that where a new file which over writes the deleted(actually not) file ends.
    for example let's say that a block contains only 8 bits of data. and suppose block 2 had the data 10001110 . Now we deleted it. And than some
    other file was being written to the block but it has only 5 bits of data so the first five bits are overwritten and the new block contains 10110110
    so isn't this data corrupted.?

    • @jeremybagwell4639
      @jeremybagwell4639 5 років тому

      The whole byte would probably be written in as 00010110. Even memory is addressed on the byte level so to put a new 5 bits in front of the 3 would require load, manipulate and store. Assembly language allows the easy manipulation of a byte. This provides more freedom for bit manipulation but it is the programmer to do it write. I would zero fill (or 1's for signed negative ints) from the top or bottom depending on if its for logic or arithmetic functions. If you just want to write the upper five bits in, you could AND it with 11111000 to zero fill the rest of the byte address. Byte splitting may be extreme but if it is the memory system of an embedded system in a muscle implant or mars sensor, that might be what you limitations are. Just my 10 cents

  • @NalinX
    @NalinX 7 років тому +2

    really wonderful presentation. I love this series. Also, Carrie Anne 😍

  • @Mike-vj8do
    @Mike-vj8do 2 роки тому

    These guys are awesome

  • @learning-master8259
    @learning-master8259 Рік тому

    Incredible and informative ...

  • @beccaknowlton4858
    @beccaknowlton4858 7 років тому +1

    It would be really nice if there was a Business CrashCourse

  • @RmSeven5
    @RmSeven5 5 років тому

    Wow, you are so amazing. I love the course.

  • @creationpower333
    @creationpower333 Рік тому

    Amazing content!

  • @رحمةعثمان-خ3ج
    @رحمةعثمان-خ3ج 7 років тому

    this is agood lesson and you are a good teacher

  • @bautistavazquez6295
    @bautistavazquez6295 7 років тому

    This is pretty cool keep it up I wanna be a hardware engineer but I like learning about everything

  • @ElderBard00
    @ElderBard00 4 роки тому

    Liked and subscribed! Loved this video. Thank you!!!

  • @santiagocerda7342
    @santiagocerda7342 7 років тому

    It would be awesome if you explain how is the data represented in a screen and the way screens work :D This videos are fantastic. Keep going!

    • @hciprof
      @hciprof 7 років тому

      Hang tight. We're getting there!

  • @tanveerB5
    @tanveerB5 6 років тому

    wow, What an explanation. Thoroughly enjoyed the video. Like The concept taking from the very basic. Thanks :):)

  • @diontaedaughtry974
    @diontaedaughtry974 6 років тому

    Thank you this was very helpful and informative 👍👍

  • @BlommaBaumbart
    @BlommaBaumbart 5 років тому +2

    2:14 - I understood that reference.

  • @bansika63
    @bansika63 4 роки тому +1

    fast speaking and confidence in subject .

  • @arnavattri5047
    @arnavattri5047 6 років тому +2

    Way awesome then Galvin Book!

  • @subamani77
    @subamani77 6 років тому

    Nice video. Good work!

  • @crashlanding9938
    @crashlanding9938 7 років тому +2

    So interesting and engaging, great work. I think this is my favorite crash course series

  • @tahir1156
    @tahir1156 5 років тому +1

    Nice programme

  • @csvscs
    @csvscs 7 років тому +2

    really enjoying this series

  • @MakeMeThinkAgain
    @MakeMeThinkAgain 7 років тому

    I so wish you would go into the details of defragmentation. Whenever I defragmented a drive I was CONVINCED I could come up with a better method. My theory is that someone came up with a very slow approach that worked well enough in the 1950s and then everyone kept using it. Prove me wrong!

  • @Morphineck
    @Morphineck 5 років тому

    First I though, man I'm weird, shouldn't red+green+blue = black. Then I was vindicated as you said that it was fun to watch the defragmentation process, I honestly thought I was the only one.

  • @JuarezJaques
    @JuarezJaques 6 років тому

    Amazing explanation!!

  • @MasterGeekMX
    @MasterGeekMX 7 років тому

    for example, File Allocation Table 32 bits (FAT32) uses in the table 12 bits to tell the size of a file in megabytes. What is the greatest number you can have with 12 binary digits? 4096, so for this reason FAT32 only allows files smaller than 4 gigabytes.

  • @JuanGarutti
    @JuanGarutti 7 років тому +1

    This was an incredible episode!

  • @proxy1035
    @proxy1035 7 років тому +2

    but how does the addressing work, it needs some form of numbers for wach byte/bit of data, like in RAM. but unlike RAM the Addresses would need to be gigantic to properly address every piece of data, like in a 930GB SSD...

    • @lotrbuilders5041
      @lotrbuilders5041 6 років тому +1

      Super Suchti Well a 64 bit Number would be enough, but most storage media store data in adressable blocks between 100 & 1000000 Bytes in size, which are then read out sequentially