Backup retention calculator

Schedule

Backup modeIncremental (delta)FullFirst backup is full, the following ones are deltas.Backups per dayFull backup interval0 = never take a new full

VM & data

VM disk usage (GiB)Used data, not provisioned sizeChange between backups (%)Share of the disk that changes each run

Retention

Backup retentionDailyWeeklyMonthlyYearlyImmutability duration (days)0 = no immutability

308 GiB

estimated repository size

6 (range 5–6)

full backups stored on the remote

14

restore points kept

81

days covered (oldest → newest)

≈ 300 GiB of full backups (6 × 50.0 GiB) + 8.0 GiB of deltas. Storing every restore point as a full backup would need 700 GiB.

How the kept restore points map to full-backup chains

Each chain keeps exactly one full backup: the oldest restore point still in it absorbs its deleted ancestors when XO merges. So the number of full backups equals the number of chains that still hold a kept point.

Full-backup chain	Kept restore points (days ago)
#21	0, 1, 2, 3, 4, 5
#20	6, 7, 8, 9
#19	15
#18	20
#14	50
#10	81

Assumptions

• One restore point per backup run (the default is one run per day).
• Week and month boundaries are approximated, and the full-backup count depends slightly on where "today" falls inside a full-backup cycle. When that matters, the calculator shows the range.