Grandfather-Father-Son scheme

  At a glance  
  • Daily incremental, weekly differential, and monthly full backups
  • Custom day for weekly and monthly backups
  • Custom retention periods for backups of each type
  Description  

Let us suppose that we want to set up a backup plan that will regularly produce a series of daily (D), weekly (W), and monthly (M) backups. Here is a natural way to do this: the following table shows a sample two-month period for such a plan.

 

Mo

Tu

We

Th

Fr

Sa

Su

Jan 1—Jan 7

D

D

D

D

W

-

-

Jan 8—Jan 14

D

D

D

D

W

-

-

Jan 15—Jan 21

D

D

D

D

W

-

-

Jan 22—Jan 28

D

D

D

D

M

-

-

Jan 29—Feb 4

D

D

D

D

W

-

-

Feb 5—Feb 11

D

D

D

D

W

-

-

Feb 12—Feb 18

D

D

D

D

W

-

-

Feb 19—Feb 25

D

D

D

D

M

-

-

Feb 26—Mar 4

D

D

D

D

W

-

-

Daily backups run every workday except Friday, which is left for weekly and monthly backups. Monthly backups run every fourth Friday, and weekly backups run on all other Fridays.

  • Monthly (“Grandfather”) backups are full;
  • Weekly (“Father”) backups are differential;
  • Daily (“Son”) backups are incremental.
  Parameters  

You can set up the following parameters of a Grandfather-Father-Son (GFS) scheme.

Start backup at:

Specifies when to start a backup. The default value is 12:00 PM.

Back up on:

Specifies the days on which to perform a backup. The default value is Workdays.

Weekly/Monthly:

Specifies which of the days selected in the Back up on field you want to reserve for weekly and monthly backups. A monthly backup will be performed every fourth such day. The default value is Friday.

Keep backups:

Specifies how long you want the backups to be stored in the archive. A term can be set in hours, days, weeks, months, or years. For monthly backups, you can also select Keep indefinitely if you want them to be saved forever.

The default values for each backup type are as follows.

Daily: 7 days (recommended minimum)

Weekly: 4 weeks

Monthly: indefinitely

The retention period for weekly backups must exceed that for daily backups; the monthly backups’ retention period must be greater than the weekly backups’ retention period.

We recommend setting a retention period of at least one week for daily backups.

Advanced settings:

To specify Advanced scheduling settings, click Change in the Advanced settings area.

At all times, a backup is not deleted until all backups that directly depend on it become subject to deletion as well. This is why you might see a weekly or a monthly backup remain in the archive for a few days past its expected expiration date.

If the schedule starts with a daily or a weekly backup, a full backup is created instead.

  Examples  
  Each day of the past week, each week of the past month  

Let us consider a GFS backup scheme that many may find useful.

  • Back up files every day, including weekends
  • Be able to recover files as of any date over the past seven days
  • Have access to weekly backups of the past month
  • Keep monthly backups indefinitely.

Backup scheme parameters can then be set up as follows.

  • Start backup at: 11:00 PM
  • Back up on: All days
  • Weekly/monthly: Saturday (for example)
  • Keep backups:
    • Daily: 1 week
    • Weekly: 1 month
    • Monthly: indefinitely

As a result, an archive of daily, weekly, and monthly backups will be created. Daily backups will be available for seven days since creation. For instance, a daily backup of Sunday, January 1, will be available through next Sunday, January 8; the first weekly backup, the one of Saturday, January 7, will be stored on the system until February 7. Monthly backups will never be deleted.

  Limited storage  

If you do not want to arrange a vast amount of space to store a huge archive, you may set up a GFS scheme so as to make your backups more short-lived, at the same time ensuring that your information can be recovered in case of an accidental data loss.

Suppose that you need to:

  • Perform backups at the end of each working day
  • Be able to recover an accidentally deleted or inadvertently modified file if this has been discovered relatively quickly
  • Have access to a weekly backup for 10 days after it was created
  • Keep monthly backups for half a year.

Backup scheme parameters can then be set up as follows.

  • Start backup at: 6:00 PM
  • Back up on: Workdays
  • Weekly/monthly: Friday
  • Keep backups:
    • Daily: 1 week
    • Weekly: 10 days
    • Monthly: 6 months

With this scheme, you will have a week to recover a previous version of a damaged file from a daily backup; as well as 10-day access to weekly backups. Each monthly full backup will be available for six months since the creation date.

  Work schedule  

Suppose you are a part-time financial consultant and work in a company on Tuesdays and Thursdays. On these days, you often make changes to your financial documents, statements, and update the spreadsheets etc. on your laptop. To back up this data, you may want to:

  • Track changes to the financial statements, spreadsheets, etc. performed on Tuesdays and Thursdays (daily incremental backup).
  • Have a weekly summary of file changes since last month (Friday weekly differential backup).
  • Have a monthly full backup of your files.

Moreover, assume that you want to retain access to all backups, including the daily ones, for at least six months.

The following GFS scheme suits such purposes:

  • Start backup at: 11:30 PM
  • Back up on: Tuesday, Thursday, Friday
  • Weekly/monthly: Friday
  • Keep backups:
    • Daily: 6 months
    • Weekly: 6 months
    • Monthly: 5 years

Here, daily incremental backups will be created on Tuesdays and Thursdays, with weekly and monthly backups performed on Fridays. Note that, in order to choose Friday in the Weekly/monthly field, you need to first select it in the Back up on field.

Such an archive would allow you to compare your financial documents as of the first and the last day of work, and have a five-year history of all documents, etc.

  No daily backups  

Consider a more exotic GFS scheme:

  • Start backup at: 12:00 PM
  • Back up on: Friday
  • Weekly/monthly: Friday
  • Keep backups:
    • Daily: 1 week
    • Weekly: 1 month
    • Monthly: indefinitely

Backup is thus performed only on Fridays. This makes Friday the only choice for weekly and monthly backups, leaving no other date for daily backups. The resulting “Grandfather-Father” archive will hence consist only of weekly differential and monthly full backups.

Even though it is possible to use GFS to create such an archive, the Custom scheme is more flexible in this situation.

Grandfather-Father-Son scheme