It's FOSS launches browser-based RAID calculator for Linux storage planning

It's FOSS has released a browser-based RAID calculator that helps Linux system administrators and storage planners compare RAID levels and ZFS layouts before building arrays. The tool computes usable capacity, drive failure tolerance, storage efficiency, and power draw estimates based on user-input drive counts, sizes, and classes. A notable feature estimates rebuild risk by calculating the probability of hitting an unrecoverable read error during array reconstruction, using manufacturer URE ratings to show why RAID 6 and RAIDZ2 are generally recommended for large modern drives.

The calculator supports standard RAID levels (0, 1, 5, 6, 10) and ZFS configurations (mirror, RAIDZ1, RAIDZ2, RAIDZ3), with a mixed-drive mode for heterogeneous arrays. All computation happens client-side; saved configurations and shareable links encode parameters locally without server communication. The tool explicitly covers compatibility with Linux software RAID implementations used by Synology, QNAP, UGREEN, and TrueNAS systems.

Calculator capabilities and technical methodology

• Capacity and redundancy formulas: Implements standard RAID calculations (RAID 0: N×S, RAID 5: (N−1)×S, RAID 6: (N−2)×S, RAID 10: N÷2×S) plus ZFS RAIDZ variants, with minimum drive counts enforced per layout.
• Rebuild risk estimation: Multiplies total bits read during rebuild by the drive's URE rating to estimate probability of encountering at least one unreadable sector; example given shows 85% risk for 4×8TB RAID 5 with consumer drives (10¹⁴) versus 17% with NAS drives (10¹⁵).
• Mixed-drive support: Offers a mode for non-uniform drive sizes, using the smallest drive as the capacity baseline S for array calculations.
• Power estimation: Uses typical per-drive wattage values (3.5" HDD 6.5W, 2.5" HDD 2.5W, SATA SSD 2.0W, NVMe SSD 4.0W) to compute array power draw and annual kWh assuming 24/7 operation.
• Client-side architecture: All processing occurs in the browser with no data transmission; saved states and shareable links contain encoded local parameters rather than stored server data.

Why it matters

This tool addresses a persistent gap in Linux storage planning by making RAID and ZFS trade-offs tangible for administrators who might otherwise default to familiar but potentially risky configurations. The rebuild risk visualization directly supports the community's ongoing push toward RAIDZ2/RAID 6 for large arrays, reinforcing practices that reduce data loss incidents in home labs, small business servers, and NAS builds running Linux mdadm or OpenZFS.