Backup types Flashcards
This is a backup rotation scheme that rotates backup media sets throughout the backup process to minimize wear and failure of tape backup media. For example, when using this method with four backup tapes labeled A, B, C, and D, a total of 16 days of backups can be maintained with just 4 tapes. Tape A is used every odd-numbered day for 16 days. Tape B is used on days 2, 6, 10, and 14. Tape C is used on days 4 and 12. Tape D is used on days 8 and 16. This allows Tape A to be overwritten every other day, while Tapes B is overwritten every four days and Tapes C and D are overwritten every 8 days
The Tower of Hanoi
The Tower of Hanoi
The Tower of Hanoi is a backup rotation scheme that rotates backup media sets throughout the backup process to minimize wear and failure of tape backup media. For example, when using this method with four backup tapes labeled A, B, C, and D, a total of 16 days of backups can be maintained with just 4 tapes. Tape A is used every odd-numbered day for 16 days. Tape B is used on days 2, 6, 10, and 14. Tape C is used on days 4 and 12. Tape D is used on days 8 and 16. This allows Tape A to be overwritten every other day, while Tapes B is overwritten every four days and Tapes C and D are overwritten every 8 days
This backup rotation scheme is widely used to combine full and incremental backups to reduce backup time and enhance storage security. The grandfather is a full backup that is stored off-site once per month. The father is a weekly full backup that is conducted. The son is an incremental or differential backup conducted each day. For example, each Monday a full backup can be conducted which becomes the father. Then, each day of the week a son is created by performing an incremental or differential backup. Once per month, a full backup is conducted to become the grandfather.
The grandfather-father-son (GFS)
The grandfather-father-son (GFS)
The grandfather-father-son (GFS) backup rotation scheme is widely used to combine full and incremental backups to reduce backup time and enhance storage security. The grandfather is a full backup that is stored off-site once per month. The father is a weekly full backup that is conducted. The son is an incremental or differential backup conducted each day. For example, each Monday a full backup can be conducted which becomes the father. Then, each day of the week a son is created by performing an incremental or differential backup. Once per month, a full backup is conducted to become the grandfather.
This policy states that an organization should create (3) one primary backup and two copies of the data, (2) save the backups to two different types of media, and (1) keep at least one backup copy off-site.
3-2-1 Backup rule
3-2-1 Backup Rule
The 3-2-1 backup rule states that an organization should create (3) one primary backup and two copies of the data, (2) save the backups to two different types of media, and (1) keep at least one backup copy off-site.
This backup scheme uses a set number of tapes and overwrites the oldest tape with the newest information. For example, if there are 7 tapes in use, every evening a new backup is conducted over the previous week’s daily backup. To have a longer amount of days of backups, a technician simply needs to increase the number of tapes from 7 to 14 or 21.
The First In First Out (FIFO) backup scheme
The First In First Out (FIFO) backup scheme
The First In First Out (FIFO) backup scheme uses a set number of tapes and overwrites the oldest tape with the newest information. For example, if there are 7 tapes in use, every evening a new backup is conducted over the previous week’s daily backup. To have a longer amount of days of backups, a technician simply needs to increase the number of tapes from 7 to 14 or 21.
Incremental Backup
Backing up only changes to the data since the last full backup on the first backup since Full Backup, then backing up only changes since the last of this same type of backup. Restoration requires that you use all of the tapes to fully restore.
Backing up only changes to the data since the last full backup on the first backup since Full Backup, then backing up only changes since the last of this same type of backup. Restoration requires that you use all of the tapes to fully restore.
Incremental Backup
Differential Backup
A differential backup captures all changes made since the last full backup. It accumulates all changes since the last full backup, regardless of whether previous differential backups have been taken or not. Full restoration requires the full backup and the last differential backup.
This backup captures all changes made since the last full backup. It accumulates all changes since the last full backup, regardless of whether previous differential backups have been taken or not. Full restoration requires the full backup and the last differential backup.
Differential Backup
