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Suppose you make a full backup the first Sunday of each month, a differential backup on each of the other Sundays, and an incremental backup every Tuesday and Thursday. Today is the 12th, which is the second Wednesday of this month. Which files (using the latest version available for each) would need to be combined to create a current synthetic full backup?

a. One full backup
b. One full backup and two differential backups
c. One full backup, one differential backup, and one incremental backup
d. One full backup, one differential backup, and two incremental backups

User Demigod
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Final answer:

The correct answer is c: a current synthetic full backup as of the second Wednesday would consist of the last full backup, the most recent differential backup from the second Sunday, and the one incremental backup from Tuesday.

Step-by-step explanation:

The correct answer is option c. On the 12th, which is a Wednesday, if we want to create a current synthetic full backup, we would start with the last full backup, which occurred on the first Sunday of the month. Since today is the second Wednesday, there would have been a differential backup made on the second Sunday. Although incremental backups happen on Tuesdays and Thursdays, there would have been only one incremental backup since the last differential backup, which would have been on Tuesday, the 11th. Therefore, you would combine the last full backup, the most recent differential backup, and the most recent incremental backup to create a synthetic full backup.

To create a current synthetic full backup on the second Wednesday of the month, we need to consider the latest versions of each backup. Based on the given backup schedule, we have:

1 full backup on the first Sunday of the month

1 differential backup on each of the other Sundays. Since today is the second Wednesday, there have been 2 Sundays since the first Sunday of the month, resulting in 2 differential backups.

1 incremental backup every Tuesday and Thursday. Since today is a Wednesday, there have been 2 Tuesdays and 2 Thursdays since the first Sunday of the month, resulting in a total of 4 incremental backups.

To create a synthetic full backup, we combine the latest full backup with the latest differential backup and the latest incremental backup. Therefore, we need one full backup, one differential backup, and one incremental backup.

User Hex C
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