Backup window calculator
A full backup is bounded by throughput. An incremental one is bounded by how much actually changed.
%
MB/s
hours
Full backup time
6.944hours
- Incremental backup time
- 0.2083 hours
- Full backup
- 6:56:40
- Incremental backup
- 0:12:30
- Full backup fits the window
- 1
- Throughput needed to fit
- 347.2 MB/s
Show the working
- Data to protect = 20
- Daily change rate = 3
- Backup throughput = 400
- Available window = 8
- Compression ratio = 2
- full_bytes = 20 * 1e12 / 2 = 10 000 000 000 000
- incr_bytes = 10 000 000 000 000 * 3 / 100 = 300 000 000 000
- Full backup = 10 000 000 000 000 / (400 * 1e6) = 25 000
- Incremental backup = 300 000 000 000 / (400 * 1e6) = 750
- Full backup time = 25 000 / 3600 = 6.944 44
- Incremental backup time = 750 / 3600 = 0.208 333
- Full backup fits the window = 6.944 44 <= 8 ? 1 : 0 = 1
- Throughput needed to fit = 10 000 000 000 000 / (8 * 3600) / 1e6 = 347.222
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- time = data volume / compression / throughput
Restore time is the number that matters in an outage, and it is usually worse than backup time.