Backup Chain Retention Capacity Planner

How to use Backup Chain Retention Capacity Planner

Enter one full-backup size, a full cadence and one incremental size per day. Keep the last chosen restore points, retain each complete dependency chain, and inspect daily space before and after retention.

1. Use the example as the schema; replace its labels and entered model assumptions.
2. Enter one full-backup size, a full cadence and one incremental size per day. Keep the last chosen restore points, retain each complete dependency chain, and inspect daily space before and after retention.
3. Calculate, inspect the complete witnesses and limitations, then copy or download the JSON report.

Good to know

• One daily point for 1–366 days, a full cadence and retention count of 1–366. Byte strings are unsigned whole values at most 1,000,000,000,000,000. Full size must be positive; increments on full days must explicitly be "0". Dates remain in Gregorian years 1900–9999.
• Full size stays at your entered value. Forward increments require every file since their base. Newly written bytes coexist with all previous physical files before retention; older bases and intermediates survive while a kept point depends on them.
• Generic assumption ledger only. No real storage scanning/deletion, failed jobs, metadata overhead, deduplication, compression, synthetic/forever-forward merges, GFS/differential policy, immutability or vendor configuration guarantee.
• Local calculation with no upload, input persistence or outside lookup. Model JSON is limited to 30,000 characters and 10,000 values. Decimal quantities are strings with up to six places; count fields use plain JSON integers. Exact fractions are capped at 8,192 bits. The complete JSON output is limited to 1,000,000 characters; approximate numbers preserve their stored values. Unsupported states fail explicitly.