Secondary Storage (Optical, Magnetic, Solid-State & Cloud)
Summary
TLDRThis video script delves into secondary storage, emphasizing its necessity for long-term, non-volatile data retention. It explores various storage mediums, including optical, magnetic, and solid-state drives, each with its unique characteristics like speed, durability, and reliability. The script also touches on cloud storage, highlighting its accessibility, portability, and the potential cost benefits for large-scale users. The discussion aims to educate viewers on the importance of evaluating these factors when choosing a storage solution.
Takeaways
- 💾 Secondary storage is essential for long-term, persistent, non-volatile storage that retains data even when the power is off.
- 🚀 Secondary storage devices like hard drives and SSDs require controllers and do not connect directly to the CPU, unlike main memory like RAM.
- 🔍 When evaluating secondary storage, consider key factors such as speed (both reading and writing), durability, and reliability.
- 📀 Optical storage uses a laser to read data from pits and lands on a disk, representing binary data, and is limited in capacity but portable and relatively durable.
- 🧲 Magnetic storage, like hard drives, uses electromagnets to read and write data by magnetizing or demagnetizing parts of the disk, offering large capacities but is less durable and generates heat.
- 💿 Solid-state storage (SSDs) uses flash memory with digital circuits and has no moving parts, resulting in faster read/write times, higher reliability, and less heat production, but at a higher cost per unit of storage.
- ☁️ Cloud storage is not a physical storage medium but a service that allows data to be stored on remote servers and accessed over the internet, offering portability and potentially lower costs for large-scale data storage.
- 🔄 SSDs do not require defragmentation, a process used in magnetic storage to optimize data storage by consolidating fragmented files.
- 💡 The choice between different storage technologies often comes down to balancing speed, capacity, cost, durability, and the specific needs of the user.
- 🌐 Cloud storage providers may offer multiple versions of files, enhancing data durability, but the reliability of the service can vary depending on the provider.
Q & A
What is secondary storage and why is it essential for a computer system?
-Secondary storage refers to any memory device not directly connected to the CPU, such as hard drives and optical disks. It is essential for long-term, persistent, and non-volatile storage, meaning data is retained even when the power is turned off. Without secondary storage, data would be lost every time the computer is turned off, and there would be no way to retain instructions or data for future use.
How does the speed of secondary storage differ between reading and writing?
-The speed of secondary storage, often referred to as read/write speed, can vary between reading and writing data. Typically, if a device is quick at reading data, it is also quick at writing data, but they are not always the same. The script emphasizes that speed is an important factor when evaluating secondary storage mediums.
What does durability mean in the context of secondary storage?
-Durability in the context of secondary storage refers to how much physical damage the storage medium can withstand, such as drops or impacts. It indicates whether the storage medium is likely to become completely unusable after such incidents.
How do optical storage devices read and write data?
-Optical storage devices read data by shining a light on the disk surface, which has variations in height representing binary data (pits and lands). The reflection angle differs based on whether the spot is a pit or a land, allowing the reader to determine if it represents a 1 or a 0. Data is written using a laser that burns pits into the disk.
What are the typical capacities and durability of optical storage like CDs and DVDs?
-Optical storage like CDs and DVDs typically have small capacities, usually around a gigabyte, and are not suitable for storing large amounts of data. They are fairly reliable and durable under normal conditions but can be easily damaged by scratches or mishandling.
How does magnetic storage work, and what are its advantages and disadvantages?
-Magnetic storage uses read/write heads with electromagnets to magnetize or demagnetize parts of the disk, representing binary data. The disk spins, and the read/write head can detect the magnetic state to read or write data. Advantages include large capacities and relatively low cost. Disadvantages include being less durable due to the mechanical nature, prone to damage if dropped, and generating heat and noise during operation.
What is solid-state storage, and how does it differ from mechanical storage?
-Solid-state storage, such as SSDs, uses flash memory and digital circuits for data storage without any moving parts, unlike mechanical storage like hard drives. This makes SSDs faster, more reliable, silent, and producing less heat, but they are typically more expensive per unit of storage.
Why is defragmentation not needed in solid-state drives?
-Defragmentation is not needed in solid-state drives (SSDs) because they do not suffer from the issue of data fragmentation that occurs in mechanical hard drives. In hard drives, data can become scattered across the disk, requiring defragmentation to improve access speed. SSDs manage data differently, so this process is unnecessary.
What is cloud storage, and how does it relate to other storage types?
-Cloud storage is a service that allows data to be stored on multiple servers in a remote location, accessed via the internet. It does not represent a unique storage type but rather utilizes other storage technologies like magnetic or solid-state drives. Cloud storage offers portability, as files can be accessed from anywhere with an internet connection, and can be more or less cost-effective depending on the scale of use.
How does the reliability of cloud storage services compare to other storage mediums?
-Cloud storage services are generally considered reliable, especially when provided by well-established companies. However, the reliability can depend on the specific provider and their infrastructure. While most providers aim for high uptime and data redundancy, some services may experience downtime or data loss, which could be a concern for users.
What are some factors to consider when evaluating secondary storage mediums?
-When evaluating secondary storage mediums, factors to consider include speed (read/write), durability, reliability, capacity, cost per unit of storage, portability, and the need for an internet connection (for cloud storage). Each storage type has its advantages and disadvantages in these areas, which should be weighed based on the intended use and requirements.
Outlines
💾 Secondary Storage Essentials
This paragraph delves into the concept of secondary storage, which refers to memory devices not directly connected to the CPU. Unlike main memory (RAM), secondary storage requires data to pass through controllers and lacks a direct channel to the CPU. It's crucial for long-term, persistent, non-volatile storage, ensuring data retention even when the power is off. The paragraph introduces key terms for evaluating secondary storage: speed (both reading and writing), durability (resistance to damage), and reliability (likelihood of failure over time). It also touches on the importance of these storage mediums, highlighting that computers rely on them for permanent data storage and instruction retrieval.
📀 Exploring Secondary Storage Technologies
The second paragraph explores various secondary storage technologies, starting with optical storage, which uses pits and lands on a disk to represent binary data (1s and 0s). Data is read using a laser, which detects variations in the disk's surface to interpret data. Writing data involves burning pits into the disk with a laser. Optical storage, such as CDs and DVDs, is noted for its portability and durability but is susceptible to damage from scratches. Magnetic storage, exemplified by hard drives, uses electromagnets to read and write data by magnetizing or demagnetizing parts of the disk. Hard drives offer large capacities and are cost-effective but are less durable and can fail over time. The paragraph also mentions the noise and heat generation associated with mechanical硬盘. Solid-state storage, like SSDs, is highlighted for its speed, reliability, and lack of mechanical parts, making it silent and heat-efficient. However, it's more expensive per gigabyte compared to hard drives. The paragraph concludes with a brief mention of cloud storage, which relies on remote servers and internet access, offering portability and the potential for data versioning but requiring a stable internet connection.
Mindmap
Keywords
💡Secondary Storage
💡Non-volatile Storage
💡Speed
💡Durability
💡Reliability
💡Optical Storage
💡Magnetic Storage
💡Solid-State Storage
💡Cloud Storage
💡Defragmentation
Highlights
Secondary storage is essential for long-term persistent storage and must be non-volatile to maintain data when power is off.
Secondary storage devices like hard drives require controllers and cannot connect directly to the CPU.
Key evaluation factors for secondary storage include speed, durability, and reliability.
Speed in secondary storage refers to both reading and writing data, which are often different but related.
Durability pertains to the physical robustness of storage devices, such as resistance to damage from drops.
Reliability indicates the expected lifespan and the likelihood of the device failing over time.
Optical storage uses laser technology to read data from variations in disk surface height.
Magnetic storage, such as hard drives, uses electromagnets to read and write data by magnetizing disk surfaces.
Solid-state storage, like SSDs, uses digital circuits and has no moving parts, offering faster read/write times.
Cloud storage is a remote data storage service accessed via the internet, often using magnetic or solid-state storage.
Cloud storage providers may offer versioning, allowing users to access and revert to older data versions.
The reliability of cloud storage can vary, with some services potentially experiencing more downtime.
Portability is a significant advantage of cloud storage, as data can be accessed from any internet-connected device.
Costs for cloud storage can be influenced by economies of scale, with larger companies potentially benefiting more.
Environmental considerations may favor cloud storage due to potential energy cost reductions for large-scale data storage.
For personal use, cloud storage might be more expensive due to billing models that charge for ongoing storage rather than a one-time purchase.
Transcripts
when I look at secondary storage which
is any memory device not directly
connected to the CPU so main memory like
RAM has its own buses that connect
directly to the CPU secondary storage on
the other hand has to go through in
Palpa Challenger has to go through
controllers it can't it hasn't got a
direct channel to a CPU and you need
secondary storage so you've got
long-term persistent storage ie
non-volatile storage meaning the data is
kept when power is turned off you can't
have a computer system without having at
least a connection even a very first
instance to secondary storage you need
to have a permanent store of dates you
can't lose your data every time you turn
the computer off because how would you
turn on again you need a place to get
your instructions from when you're
evaluating secondary storage mediums
which we're going to look at Miss video
there are some key words you should
really be using some buzzwords or impact
as you buy talk about how meant to its
by defining each one speed image context
phone means both reading speed and
writing speed so reading data from the
devices and also writing data for the
devices but usually they're not the same
but usually if one device is very quick
to read data it's also going to be very
quick to write data usually durability
is how much damage you can kind of
sustain if you dropped it for example is
it going to complete smash not that I'd
advise doing of anything and also
reliability isn't going to work overtime
is there a drop of foam where it should
probably or
on average stop working for example hard
drives are surprisingly unreliable in
the sense we often stop working a couple
of years into they into their life if
you look at the average of over major
brands they drop off quite quickly quite
worryingly quickly actually so really
you should be using these words when
you're evaluating secondary storage
let's not look at some secondary storage
technology the first one being optical
storage which stores with data by Royal
data stored as binary so I have a 1 or 0
there in stores it has variations of
height on the disk surface so the disk
is full of almost invisible pits and
loud zap it is a little divots and
Landers of C wears flats
so app it might represent a zero alarm I
represent a 1 in binary and so when
lights shined on this disc in a reader I
Steve again when light is shined on a
land a flat bit it just gets reflected
up so it's quite a standard reflection
of that point but if it's a pit it
bounces off a different angle so it can
tell when it reads this whether or not
it's representing a one or a zero that's
how you read data off a optical disk but
you write data with a laser but burns
fees variations burns were pits into the
disk so a mini evaluation per unit in
terms of a single DVD a single CD they
have a small capacity you don't get you
don't exactly have like 50 movies stored
on a single CD because you can't make
capacities not by large usually it's
around a gigabyte in a kind of typical
one obviously for like blu-ray it would
be more they are fairly reliable and
durable but can be easily damaged so
durable is a kind of funny one in this
context because you can kind of look
after a CD quite easily but then you can
damage it very easily if you know I mean
so scratches of course but we are very
portable very easy to transport carry
you can store loads of them very easily
let's unlock a magnetic storage which
instead of using a laser and a light to
read write data this uses read/write
head server containing electromagnets
and so instead of a little divot being
created in the disk like optical parts
of the disks are either made magnetized
or demagnetized by the electromagnets in
this little read/write head here and so
the disk spins and it can make parts of
it magnetized with a magnetized when
you're writing and it can tell if it's
magnetized or demagnetized when it's
reading this is a hard drive where hard
drivers come at the whole unit whereas
obviously the disk for hard disk is no
surprises for disk and in terms of
evaluation they are comparatively have a
very large capacity you can have
terabytes of magnetic storage of to
about hard disks and cheap compared to
other long-term storage mediums they're
usually quite reliable but as
before they actually often stopped
working after a certain amount of time
but we're not very durable you can
easily break them if you dropped it you
would smash four discs can break it and
they're not very important with it
generally because another example which
isn't news anymore is cassettes a
magnetic tape which would be very
portable and also you can have external
disk drives which are also magnetic but
you know generally the type of go inside
your computer aren't possible at all
because they are mechanical this is a
mechanical disc obviously it's spinning
around
it is often quite noisy and also
generate heat which is a major
disadvantage but usually it's the
capacity and the cheapness of it but
kind of over wall so you have a
disadvantages the third type of storage
when we're looking at is solid-state
storage and this is a solid-state drive
an SSD and this is a type of flash
memory which is non-mechanical so hasn't
got a little spinning disk in it like
the other two this consists of just
digital circuits logic gates for keep
datum and you can change your masters
for storages we can't really talk about
how will be work exactly because it's
too complicated
it's just loads of little circuits you
kind of value it from quite nicely they
are a lot faster they read write times a
lot faster than hard drives for example
but per capacity or per unit sorry very
lot more expensive so 128 gigabyte SSD
might cost the same as a terabyte hard
drive if I'm right been a while since
I've bought either one of them they are
quite reliable compared to other types
because there are no mechanical was less
we can go wrong in that sense if you
don't know this means don't worry too
much but we don't need defragmentation
this will be covered at some future
point where and this is where data's
kind of shuffled around so it's more
efficient because they can often get
misplaced and spread about in a hard
drive but we don't need to do it with an
SSD there's another much smaller
capacitive and magnetic hard disks
because they have because they're more
expensive sorry they are silent but we
don't really produce much heat which is
another advantage you might want to talk
about mostly because a majority people
can't afford to have a or two terabyte
lots of SSDs
my computer a SSD is often use to store
the operating system because it's very
quick to load so when you turn the
computer on it's very fast to load but
then will have most of our data stored
in a mechanical magnetic hard drive for
final medium when we're looking at is
cloud storage it comes up all the time
and exams it's really a one of Examiners
favorite topics cloud storage this is
where data stored on multiple servers in
a remote location and you access it
across the internet and this is whether
not an out because it's not its own
storage in its own right it's not a
unique type of storage they use it
you've sadly to be magnetic and still
will use something else but now because
of a speed and because it is getting
cheaper they'll increasingly use
solid-state storage so this isn't its
own type of storage it will use the
other two as I say you'll access
customer through the internet through a
web-based API application programming
interface just a way to access your data
online usually or for a nap often so now
for a quick evaluation these are just
suggested points whatever way as of the
other ones I've shown you so far lots of
things you can talk about here these are
just pointers often multiple versions
are kept by cloud storage providers so
if you need to go back to an old version
that's usually okay so that's kind of
counts for durability in my sense but
depending on who you choose the service
might not be reliable I would say most
cloud storage providers are reliable
because if they weren't first of all
it's huge startup costs you become a
cloud storage providing initial
Microsoft of Google it's hard to just
start one but so it usually they are
reliable but for may not be the service
may be down quite a lot which is quite
worrying so you wouldn't want to use
that clearly very very very portable
files can be accessed anywhere on the
internet so totally portable but you
need internet connection that is another
the validation point you can make a
third more niche point is about four
costs mainly due to economies of scale
large companies using cloud storage
providers to store all their company's
data may be cheaper and probably reduce
energy costs which is a really nice
environmental evaluation point but for
smaller users it may be more expensive
because the model be storing that much
data might get billed monthly as opposed
to just a one-off pain
for larger hard drive for example so for
the first free technologies we looked at
make sure you understand how they work
roughly the solid-state ones are
slightly harder to talk about but they
are just digital circuits you won't be
expected to know more from that but
clerestory just slightly more about
evaluation but they do use magnetic and
now increasingly solid-state storage
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