Technical Implementation(Storage) Flashcards
Explain the difference between disaster avoidance and disaster recovering
Avoidance - Methods to try to avoid the loss of data
Recovery - Methods use to get the data back after loss of data
Give an example of a disaster avoidance strategy?
Uninterrupted Power Supply
What is responsible for centralising distributed storage?
DDBMS (Distributed Database Management System)
Describe distributed storage
Distributed storage is when data is stored over more than one computer, the data is centralised using a DDBMS(Distributed Database Management System) which synchronises all data. All data is basically backed up instantaneously.
Give some advantages of distributed storage
<ul>
<li>More storage and more processing power than if it was just stored on one individual computer</li>
<li>Easy to expand</li>
<li>User has a fairly local version of database which will respond quickly to your request</li>
</ul>
Give an example of a company who uses distributed storage to store their data
Facebook, Amazon, Google
Describe Offline Storage
Offline storage is a method of storing data that is physically removed from the network. It cannot be accessed until physically connected to a network. It is often used to transport data. An example of offline storage is backup tapes.
Give an advantage and a disadvantage of offline storage compared to distributed storage
Advantages - Cheaper to store - More secure as no digital access Disadvantages - Harder to expand
Compare cloud technology to local servers in terms of
<ul>
<li>Cost</li>
</ul>
Cost - <strong>Cloud</strong> tends to have monthly fees, which relate to number of services and capacity of storage, cloud is more expensive short term
<strong>Local</strong> does not have subscription fees but they will need licensing fees initially to pay for software to (for example) manage email servers
Morgan is trying to store her company’s data. She has to decide whether to store it using cloud or local storage. In three months, Morgan’s business is expanding as they accommodate 200 new workers. What storage would you recommend Morgan purchasing?
It would be better to go for <em><strong>Cloud</strong></em> storage due to the fact it is easier to expand, she won’t have to worry about the technicalities, her business will just pay more and she will be able to expand her cloud storage capacity.
Jake has a small company and is looking to minimise his use of bandwidth to save the company money. He is looking for a storage solution, and is deciding between cloud and local. Which one would you recommend and why?
It would be better to go for <em><strong>Local </strong></em> because it requires less bandwidth. With cloud, there will be higher use of bandwidth due to constant uploading of data onto the cloud, so local would be the way forward for Jake.
Compare the installation costs of local vs cloud storage.
Cloud - Installation costs are not worried about, the cloud provider deals with that, the user just has to pay to subscribe to cloud storage.
Local - Costs for purchasing servers and the cost is likely to re-occur every 5 years as you replace servers
Describe a full backup and a disadvantage of this method of backing up files
A full backup is where all the data on a system is copied regardless of whether there has been any change or not. It is often stored on a different server or a digital magnetic tape.
Disadvantage:
<ul>
<li>Slow and requires lots of memory space</li>
</ul>
Describe the different between <em>differential</em> and <em> incremental </em> backups
Differential - type of backup method that saves any changes in the data since LAST FULL BACKUP
Incremental - type of backup method that saves any changes in data since BACKUP OF ANY KIND
Why are magnetic hard disks and solid state devices not often used for back-up?
Because normally large amounts of data is required to be copied and this would incur LARGE FEES if a magnetic hard disk or a solid state device was used
What does DAT and DLT stand for?
DAT - Digital Audio Tape
DLT - Digital Linear Tape
Describe DAT/DLT as a method of backup
DAT(Digital Audio Tape) and DLT(Digital Linear Tape) are both methods of magnetic storage that can be used for backup. They both record data in a digital form and typically have a capacity of about 150GB. They are typically used for long term storage of data.
Describe an advantage of DAT/DLT as a method of backup
<ul>
<li>Cost effective as cassettes are cheaper than servers</li>
</ul>
Describe <em>‘Optical’</em> as a method of backup
Optical is a method of backup where the data is stored on CDs,DVDs and Blurays. Optical backup is often used for archiving data and can only cope with small capacities.
Describe onsite backup as a location for backup and give an advantage and a disadvantage of this location
Onsite backup is where the backup is kept in the same location as the ‘live’ data
Advantages
<ul>
<li>No need to connect to internet to upload data</li>
<li>Able to get fast access to data</li>
Disadvantages
<li>Can be destroyed along with live copy due to fire or water damage</li>
<li>If ransomware attacks, both copies of data will be encrypted</li>
</ul>
Describe cloud as a location of backup and what methods of backup it uses
Cloud is where data is stored on remote servers accessed by the internet
It uses off site repository and distributed backup as methods to store the data.
What does RAID stand for?
Redundant Array of Independant Disks
Describe how RAID works as a form of backup
RAID(Redundant Array of Independent Disks) is a form of backup which has seven recognised RAID levels(from RAID0 to RAID6). These levels all employ different methods of backup. RAID1 commonly uses disk mirroring.
What form of backup does RAID1 usually use?
Disk Mirroring
- Accidental Deletion may occur
- If infection occurs, and disk mirroring is used, it could spread through many copies
- Noise/Interference affecting cables
- The need to resend due to errors
- Magnetic Storage
- Large storage capacity
- Data is stored on platters
- Random Access
- Long plastic strip covered in metal oxide
- Each track(circles on the disks)is broken into sectors which store the data
- Serial Access
