What is differential backup?

What is differential backup?

• It is like any other backup ; just a fancy name
• backup of changes after the last full backup
• A quick backup
• backup of changes since last incremental backup 

EXPLANATION

A differential backup backs up only the files that changed since the last full backup. For example, suppose you do a full backup on Sunday. On Monday you back up only the files that changed since Sunday, on Tuesday you back up only the files that changed since Sunday, and so on until the next full backup. The amount of data being backed up grows with each differential backup until the next full back up

SOURCE

https://www.acronis.com/en-us/articles/incremental-differential-backups/

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Which of the following is not a part of 3-2-1 backup strategy?

Which of the following is not a part of 3-2-1 backup strategy?

• Different backup media vendors
• Multiple backup copies
• Different backup storage location
• Different backup media types 

EXPLANATION

The 3-2-1 backup strategy, also known as the Rule of Three, says that you should have at least 3 different copies of the data on at least 2 different types of media in at least 1 different location.

SOURCE

https://quiz.techlanda.com/2017/11/which-of-following-is-not-part-of-3-2-1.html

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Which type of backup site has the fastest recovery time?

Which type of backup site has the fastest recovery time?

• Hot site
• Cold site
• Middle Site
• Warm Site 

 

EXPLANATION

A hot backup site is a full duplicate of the source data center, so has the fastest recovery time but also the highest price tag. The warm site is a scaled-down hot site,
which includes basics like power, networking, and telecommunications that are active at all times. A cold site usually includes power and physical space when not in use, giving you the longest recovery window for the cheapest price.

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In which of the following scenarios would you use a WORM backup tape?

In which of the following scenarios would you use a WORM backup tape?

• When the tape data is overwritten at random.
• When the tape data is written only once.
• When the tape data is overwritten monthly.
• When the tape or tapes are stored somewhere moist or dirty. 

EXPLANATION

WORM is an acronym for Write Once Read Many. WORM devices are physically designed to only ever be written to once but can be read from many times.

SOURCE

https://en.wikipedia.org/wiki/Linear_Tape-Open#WORM

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Grandfather-Father-Son (GFS) is a(n):

Grandfather-Father-Son (GFS) is a(n):

• Hierarchical UML design pattern
• Common backup media rotation strategy
• Inheritance design standard in object-oriented programming
• Layered SDN (software defined networking) design standard 

 

EXPLANATION

Grandfather-Father-Son is a common backup media rotation strategy. It employs a daily-weekly-monthly approach that addresses near-term and long-term (archival) backup concerns.
https://www.sans.org/reading-room/whitepapers/sysadmin/backup-rotations-final-defense-305

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Which of the following is not a part of 3-2-1 backup strategy?

Which of the following is not a part of 3-2-1 backup strategy?

• Different vendor
• Different copy
• Different location
• Different media 

 

EXPLANATION

The 3-2-1 backup strategy, also known as the Rule of Three, says that you should have at least 3 different copies of the data on at least 2 different types of media in at least 1 different location.

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You take a full backup every Sunday and a daily differential backup each morning. Assuming you don't have software that would simplify the process, how many backups would you have to restore following a disaster on Friday?

You take a full backup every Sunday and a daily differential backup each morning. Assuming you don't have software that would simplify the process, how many backups would you have to restore following a disaster on Friday?

• 1
• 5
• 2
• 6 

EXPLANATION

With differential backups, you only need to restore the last full backup and the last differential backup. If you were using incremental backups, then you'd need to restore the last full and all intervening incremental backups for full recovery.

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How much time can a service be unavailable to meet a "five nines" uptime requirement?

How much time can a service be unavailable to meet a "five nines" uptime requirement?

• 5.3 minutes per year
• 87 hours per year
• 53 minutes per year
• 8.7 hours per year 

 

EXPLANATION

Five nines refers to a total operational potential of 99.999%. So for a 24x7 service, across a year that translates to less than 5.3 minutes of combined downtime.https://en.wikipedia.org/wiki/High_availability

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