M4 - U4 - S4 - Backups

• Keep at least one backup in a different location to the computer

  • On-site/Off-site (original data vs back-up location)

• Keep the device or media used to store backup data in a secure location

• Keep more than one copy of data

  • Different time points in time

• Make a backup regularly

  • Week vs day | when software is un/installed

The 4 main principles of backups/backing up data

• Direct/Locally Attached Storage

  • Hard disks/flash drives attached to local PC or server

• Network Attached Storage

  • Use a NAS appliance to allow multiple machines to back up to the same location

• Cloud Storage (off-site)

  • Back up over the Internet to cloud-based storage

  • May require substantial bandwidth

The 3 storage media previously discussed that can act as backups

True

• E.g. off-site storage helps prevent against fire & theft

• You could back up often to locally attached storage or NAS and then copy the backups to a cloud storage solution for off-site security

True or False: It is a good idea to use a combination of methods to back up data

True

• Tape drives are an example of the type of specialised media that might be used

True or False: Enterprise networks with very large amounts of data to backup may use more specialised media

False

True or False: All critical data will likely be stored in user files or shared folders

Critical Data

• May include data such as confidential, proprietary, and/or personal information

• Could be stored in a settings file outside of the normal data areas

  • or be located within a database or message store

• Must ensure copies have the same security policies and access controls as the original

RDBMS (Relational Database Management System)

• Type of database system in which data is constantly being used

  • E.g. MySQL

• Each change in the database is referred to as a transaction

Transaction

• A change in a database

• ____s that add, amend, or retrieve a record might comprise several read/write operations

  • These operations are bundled as _____ to ensure that the data records remain consistent

  • and are not corrupted by partially completed write operations

“Transaction-aware”

Ordinary copy backup methods are not _____

• So cannot be used to back up a database

True

True or False: Database backup requires the use of software dedicated to that purpose

Replication/Replicas

• A copy (or mirror) of the database hosted on a separate server

• Transaction must be committed/performed to both the master database and the ___ before considered complete

  • Provides redundancy in the case that the master database server is damaged

True

• This way, you are protected if a user e.g. accidentally deletes a record and this action is propagated/registered in the replica

True or False: You should also back up your replica to a point in time

Transaction Log

• Critical component of a relational database management system (RDBMS) that records all changes made to a database

• Important to include in backup operations

  • Support rollbacks of mistaken transactions and recovery from critical disasters

Read-only copies

• User may want to make ___ copies of the database

• Users cannot change/edit any information in this version of the file/database/document

• Function is supported through snapshots

Snapshot(s)

• A static, read only view of the source database

• Useful for keeping historical records of changes to the database

  • or for recovering from really serious administrative errors that cannot be corrected through transaction rollbacks

System Backup

• Copy of the OS and installed applications

  • Allows workstation or server to be recovered without having to manually reinstall software and reconfigure settings

True

• Typically, the operating system would have to be reinstalled, then the backup applied to the new OS to recover the old configuration

True or False: Older methods of system backup could involve lengthy recovery procedures

Bare Metal Backup

• A backup that can be applied directly to a partitioned drive without the separate step of reinstalling the OS

• Works by making an image

Backup Software Image Creation

• Backup software provides a recovery boot disk which enables the system to connect to the recovery media

  • E.g. external hard drive or network drive storage media

• Drawback:

  • System images require multi-gigabyte storage media

  • Can be time-consuming to create

True

• This is because system image creation can be time-consuming to create

True or False: System image creation works best if the system configuration is kept fairly static and user data is stored separately from the OS volume