Enabling Harmonized Scheduling
When you combine multiple types of schedules, Veeam Backup for AWS applies the harmonization mechanism that allows you to leverage restore points for long-term retentions instead of taking a new restore point every time. The mechanism simplifies the backup schedule, optimizes the backup performance and reduces the cost of retaining restore points.
With harmonized scheduling, Veeam Backup for AWS can keep restore points created according to a daily, weekly or monthly schedule for longer periods of time: EFS backups and backup copies can be kept for weeks, months and years.
For Veeam Backup for AWS to use the harmonization mechanism, there must be specified at least 2 different schedules: one schedule will control the regular creation of restore points, while another schedule will control the process of storing restore points. In terms of harmonized scheduling, Veeam Backup for AWS re-uses restore points created according to a more-frequent schedule (daily, weekly or monthly) to achieve the desired retention for less-frequent schedules (weekly, monthly and yearly). Each restore point is marked with a flag of the related schedule type: the (D) flag is used to mark restore points created daily, (W) — weekly, (M) — monthly, and (Y) — yearly. Veeam Backup for AWS uses these flags to control the retention period for the created restore points. Once a flag of a less-frequent schedule is assigned to a restore point, this restore point can no longer be removed — it is kept for the period defined in the retention settings. When the specified retention period is over, the flag is unassigned from the restore point. If the restore point does not have any other flags assigned, it is removed according to the retention settings of a more-frequent schedule.
Consider the following example. You want a backup policy to create backups of your file systems 1 time a day, to keep 3 daily backups in the backup chain, and also to keep one of the created backups for 2 weeks. In this case, you create 2 schedules when configuring the backup policy settings — daily and weekly:
- In the daily scheduling settings, you select hours and days when backups will be created (for example, 7:00 AM; Working Days), and specify a number of days for which you want to keep daily restore points in a backup chain (for example, 3).
Veeam Backup for AWS will propagate these settings to the schedule of a less-frequent schedule (which is the weekly schedule in our example).
- In the weekly scheduling settings, you specify which one of the backups created by the daily schedule will be retained for a longer period, and choose for how long you want to keep the selected backup.
For example, if you want to keep the daily restore point created on Monday for 2 weeks, you select 7:00 AM, Monday and specify 14 days to keep in the weekly schedule settings.
According to the specified scheduling settings, Veeam Backup for AWS will create EFS backups in the following way:
- On the first work day (Monday), a backup session will start at 7:00 AM to create the first restore point. The restore point will be marked with the (D) flag as it was created according to the daily schedule.
Since 7:00 AM, Monday is specified in weekly schedule settings, Veeam Backup for AWS will also assign the (W) flag to this restore point. As a result, 2 flags (D,W) will be assigned to the restore point.
- On the same week, after backup sessions run on Tuesday and Wednesday, the created restore points will be marked with the (D) flag.
- On the fourth work day (Thursday), after a backup session runs at 7:00 AM, the created restore point will be marked with the (D) flag.
By this moment, the earliest restore point in the backup chain will get older than the specified retention limit. However, Veeam Backup for AWS will not remove the earliest restore point (7:00 AM, Monday) with the (D) flag from the backup chain as this restore point is also marked with a flag of a less-frequent schedule. Instead, Veeam Backup for AWS will unassign the (D) flag from the restore point. This restore point will be kept for the retention period specified in the weekly scheduling settings (that is, for 2 weeks).
- On the fifth working day (Friday), after a backup session runs at 7:00 AM, the created restore point will be marked with the (D) flag.
By this moment, the restore point created on Tuesday with the (D) flag will get older than the specified retention limit. Veeam Backup for AWS will remove from the backup chain the restore point created at 7:00 AM on Tuesday as no flags of a less-frequent schedule are assigned to this restore point.
- Veeam Backup for AWS will continue creating restore points for the next week in the same way as described in steps 1–4.
- On week 3, after a backup session runs at 7:00 AM on Monday, the earliest weekly restore point in the backup chain will get older than the specified retention limit. Veeam Backup for AWS will unassign the (W) flag from the earliest weekly restore point. Since no other flags are assigned to this restore point, Veeam Backup for AWS will remove this restore point from the backup chain.