Partition Resizer Open Source

This tool models a disk and its partitions to plan safe resizing that respects capacity and minimum sizes. It accepts total disk size, per-partition current sizes, minimums, and optional target sizes, then returns a feasible plan without performing changes. It is intended for IT admins, storage engineers, and system owners performing offline planning for OS upgrades, data reallocation, or multi-boot reconfigurations.
Conceptually, the tool enforces constraints (min_size per partition) and ensures the sum of proposed sizes does not exceed total capacity, while aiming to minimize data movement. When a desired plan would overflow the disk, it proposes alternatives such as reducing less critical partitions or increasing priority partitions, and can compare multiple scenarios. It can export the resulting plan for documentation or scripting.
Core value lies in auditable, repeatable planning that reduces risk, improves change-control discipline, and provides actionable steps before any live resizing. Core features include per-partition sizing, feasibility flags, and scenario comparison; advanced users can export in JSON or CSV for integration with OS tooling. Use cases include reclaiming space after large data growth, creating dedicated partitions for backups, or preparing space for a new OS installation.