A retention policy is defined in terms of (1) the maximum number of snapshots to be retained and (2) the number of hourly, daily, weekly, and monthly snapshots to retain. When a server’s retention policy is disabled, the maximum number limitation remains in effect.
How snapshots are merged: A day’s worth of hourly snapshots are merged into a single snapshot for that day, a week’s worth of daily snapshots are merged into a single snapshot for that week, a month’s worth of weekly snapshots are merged into a single snapshot for that month. Merging snapshots reduces the amount of space needed to store them.
Once the number of stored snapshots meets the limits of the retention policy, as new snapshots are created, the oldest ones are deleted automatically.
Retention policies are defined for each client account by Acronis engineers based on specifications provided by the client. A retention policy is assigned to individual servers for which there are snapshots, this is also done by Acronis engineers.