Partition Resizer

Partition Resizer operates on a provided ISO disk image to expose its partition table, identify each partition's type and filesystem, and determine safe target sizes. It is designed for IT ops, virtualization teams, and software developers who build bootable ISOs or VM-ready images. The tool preserves boot sectors and metadata while proposing space reallocation, ensuring that critical partitions remain intact. It supports common filesystems and can work with both MBR and GPT layouts. The core value is deterministic, repeatable resizing that minimizes manual tooling and reduces the risk of data loss during image preparation.
Conceptually, the tool reads the ISO, parses the partition map, computes minimum and maximum allowable sizes per partition based on filesystem constraints and block size, and then re-maps partitions to accommodate the new scheme. It then performs filesystem-aware adjustments (resize operations) and rewrites the ISO with the updated layout. The process produces a verifiable output and a machine-readable log. Unique differentiators include safety checks against overlaps, sector-alignment enforcement, and an optional preview mode that shows changes before committing. Use cases include creating leaner ISOs for cloud deployment, expanding specific OS partitions for testing, and generating consistent images for CI pipelines.
Core features include: automatic layout analysis, filesystem-aware resizing, integrity validation, and output ISO generation. Users can specify new sizes or let the tool optimize free space based on target capacity. The tool reports potential issues (e.g., insufficient free space, non-resizable partitions, or encrypted containers) and refuses risky operations. It is suitable for enterprise workflows, virtualization labs, and backup workflows where reproducibility matters. The output can be used directly in VM platforms or provisioned to cloud images. In all cases, the tool emphasizes non-destructive planning, transparent results, and traceable logs for auditing.