4.3 - Managing Backups

Question 1

Backups

Answer 1

• Incredibly important
  – Recover important and valuable data
  – Plan for disaster
• Many different implementations
  – Total amount of data
  – Type of backup
  – Backup media
  – Storage location
  – Backup and recovery software
  – Day of the week

Question 2

Full Backup

Answer 2

• Backup everything
  – All operating system and user files
• This is usually the longest
  backup process
  – It’s everything in one backup
• Might be impractical every day
  – Long backup times
  – Lots of storage space

Question 3

Incremental Backup

Answer 3

• A full backup is taken first
• Subsequent backups contain
  data changed since the last full
  backup and last incremental backup
  – These are usually smaller
  than the full backup
• A restoration requires the full backup
  and all of the incremental backups

Question 4

Differential backup

Answer 4

• A full backup is taken first
  – Subsequent backups contain data
  changed since the last full backup
  – These usually grow larger as
  data is changed
• A restoration requires the full backup
  and the last differential backup

Question 5

Synthetic backup

Answer 5

• Create a full backup
  – Without actually performing a full backup
• Synthetic backup
  – The first full backup copies every file
  – Subsequent full backups are created from
  previous backups
• Can be faster and less bandwidth intensive
  – The advantage of a full backup
  – The efficiency of an incremental backup

Question 6

Backup testing

Answer 6

• It’s not enough to perform the backup
  – You have to be able to restore
• Disaster recovery testing
  – Simulate a disaster situation
  – Restore from backup
• Confirm the restoration
  – Test the restored application and data
• Perform periodic audits
  – Always have a good backup
  – Weekly, monthly, quarterly checks

Question 7

On site vs. off site backups

Answer 7

• On site backups
  – No Internet link required
  – Data is immediately available
  – Generally less expensive than off site
• Off site backups
  – Transfer data over Internet or WAN link
  – Data is available after a disaster
  – Restoration can be performed from anywhere
• Organizations often use both
  – More copies of the data
  – More options when restoring

Question 8

Grandfather-father-son (GFS)

Answer 8

• Three separate backup rotations
  – Monthly, weekly, daily
• Twelve monthly full backups (grandfather)
  – A good choice for offsite storage
• Four (or five) weekly full backups (father)
  – Depends on which day of the month is selected
• Thirty-one daily incremental or differential backups (son)
  – Backup any daily changes

Question 9

GFS backup schedule

Answer 9

• Choose a rotation
  – Every organization is different
• Grandfather
  – Last day of every month
• Father
  – Every Monday
• Son
  – Monday through Friday

Question 10

3-2-1 backup rule

Answer 10

• A popular and effective backup strategy
  – For business or home use
• 3 copies of data should always be available
  – One primary copy and two backups
• 2 different types of media should be used
  – Local drive, tape backup, NAS
• 1 copy of the backup should be offsite
  – Offsite storage, cloud backup