--- title: "WORM Technologies Compared: Optical, Tape, Hardware, Software" date: 2026-04-09T14:05:00+02:00 author: FAST LTA canonical_url: "https://www.fast-lta.de//en/blog/worm-technologien-im-vergleich-optisch-tape-hardware-software" section: "Entries: Articles" --- ### The Four Technologies at a Glance [\#](#the-four-technologies-at-a-glance "The Four Technologies at a Glance") #### Optical Media (CD‑R, DVD‑R) [\#](#optical-media-cd-r-dvd-r "Optical Media (CD-R, DVD-R)") - **Capacity per medium:** under 5 GB, far too small for modern archives - **Access:** slow, manual media handling - **Immutability:** physical, cannot be bypassed - **Status:** obsolete; reader hardware is disappearing. Relevant only for reading legacy archives. #### Tape (WORM Cartridges) [\#](#tape-worm-cartridges "Tape (WORM Cartridges)") - **Capacity per medium:** high (multiple terabytes per cartridge) - **Access:** sequential; retrieving a single record means loading and winding a cartridge - **Immutability:** enforced by cartridge firmware, solid in itself - **Operational reality:** media handling, off-site logistics, periodic migration of every cartridge, drive and robotics maintenance, and no way to verify integrity without loading each tape - **Status:** being replaced by disk-based hardware WORM, which delivers the same immutability with random access, online verification, and no media handling #### Hardware WORM on Disk (Silent Cubes) [\#](#hardware-worm-on-disk-silent-cubes "Hardware WORM on Disk (Silent Cubes)") - **Capacity:** scales from terabytes upward by adding units - **Access:** random access at NAS speed; any record retrievable in seconds - **Immutability:** enforced by the storage system itself; cannot be bypassed with admin rights - **Integrity:** continuous online verification; Silent Cubes add redundant storage with erasure coding, designed for very long retention - **Cost profile:** higher entry price than generic storage, low operating effort, no media logistics - **Status:** the standard for professional compliance archiving #### Software WORM (Object Lock, Retention Flags) [\#](#software-worm-object-lock-retention-flags "Software WORM (Object Lock, Retention Flags)") - **Capacity:** whatever the underlying storage provides - **Access:** fast and flexible - **Immutability:** enforced by software; depending on configuration, privileged accounts can change policies or destroy the underlying storage - **Compliance:** acceptable only with strong organizational controls, and the weaker evidence in an audit - **Status:** useful as an additional layer, not as the sole basis for statutory archives --- ### Recommendation by Use Case [\#](#recommendation-by-use-case "Recommendation by Use Case") **Small organizations (low archive volume):** Software WORM plus strict organizational controls can be a starting point, but be aware that the burden of proof in an audit rests on your processes, not on the technology. Entry-level hardware WORM removes that risk. **Mid-sized organizations:** Hardware WORM (Silent Cubes) for the compliance archive, combined with air-gapped backups (Silent Brick System) for operational recovery. This separates the two jobs cleanly: the archive proves integrity, the backup restores operations. **Large organizations and critical infrastructure:** Hardware WORM in a multi-system, multi-site setup with replication. Erasure-coded redundancy and online integrity verification scale; media-based archives do not. **Cloud-first environments:** Object lock features provide a software WORM layer, but you depend on the provider’s implementation and jurisdiction. For records subject to statutory retention, keep the authoritative copy on hardware WORM under your own control; cloud copies are a supplement, not the primary archive. --- ### Further Resources [\#](#further-resources "Further Resources") → Audit-Proof Archiving Guide (/en/blog/revisionssicherheit-leitfaden/) → WORM Storage Fundamentals (/en/blog/worm-speicher-grundlagen/) → Software WORM vs. Hardware WORM (/en/blog/software-worm-vs-hardware-worm/) → Silent Cubes: Hardware WORM Archive Storage (/en/produkte/silent-cubes/) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### Audit-Proof Archiving Audit-proof archiving describes the legally required property of an archiving system that preserves documents completely, immutably, traceably and accessibly at all times — and that this can be demonstrated without gaps to tax authorities, auditors and data protection supervisory bodies. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/audit-proof-archiving) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### Immutable Storage Immutable storage refers to storage technologies that protect stored data from subsequent alteration or deletion — where the decisive difference lies in whether this protection is enforced at the hardware level (cannot be circumvented) or at the software level (can be circumvented by administrators with sufficient rights). [Mehr erfahren →](https://www.fast-lta.de//en/glossary/immutable-storage) ### Immutable Storage Immutable storage refers to storage technologies that protect stored data from subsequent alteration or deletion — where the decisive difference lies in whether this protection is enforced at the hardware level (cannot be circumvented) or at the software level (can be circumvented by administrators with sufficient rights). [Mehr erfahren →](https://www.fast-lta.de//en/glossary/immutable-storage) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### Immutable Storage Immutable storage refers to storage technologies that protect stored data from subsequent alteration or deletion — where the decisive difference lies in whether this protection is enforced at the hardware level (cannot be circumvented) or at the software level (can be circumvented by administrators with sufficient rights). [Mehr erfahren →](https://www.fast-lta.de//en/glossary/immutable-storage) ### Audit-Proof Archiving Audit-proof archiving describes the legally required property of an archiving system that preserves documents completely, immutably, traceably and accessibly at all times — and that this can be demonstrated without gaps to tax authorities, auditors and data protection supervisory bodies. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/audit-proof-archiving) ### Immutable Storage Immutable storage refers to storage technologies that protect stored data from subsequent alteration or deletion — where the decisive difference lies in whether this protection is enforced at the hardware level (cannot be circumvented) or at the software level (can be circumvented by administrators with sufficient rights). [Mehr erfahren →](https://www.fast-lta.de//en/glossary/immutable-storage)