Synology DSM 7.3 NAS – HDD/SSD Compatibility in the PLUS, RS, XS, XS+, SA and More

The Synology Hard Drive and SSD Support Change in DSM 7.3 Explained – What You Can/Cannot Do

With the release of DSM 7.3, Synology has formally introduced its latest and most detailed round of storage compatibility policies to date, outlining exactly which hard drives and solid-state drives are supported across its growing NAS product ecosystem. These updates arrive after several years of gradual tightening in Synology’s hardware validation process, which began in 2021 with the introduction of the HAT5300 and HAT3300 drives and became fully enforced in the 2024–2025 generation of devices. Under DSM 7.2, many of these newer systems—in particular the Plus series—were restricted to using Synology-branded drives only, effectively preventing users from creating storage pools with unverified third-party disks. This limitation led to considerable backlash from the community and power users who had relied on flexible drive choices for mixed or repurposed storage builds.

DSM 7.3 introduces a new structure to this policy, known internally as the HCL 5.0 framework, which partially relaxes those restrictions for 2025 model-year DiskStation Plus and J series NAS systems. It reinstates the ability to use non-listed hard drives and SATA SSDs for pool creation, while maintaining a degree of verification for higher-end systems such as the XS, SA, FS, and HD series. The update is significant because it rebalances Synology’s approach to drive validation, aligning reliability goals with user flexibility. In addition, DSM 7.3’s drive-handling system now displays clearer notifications within Storage Manager, differentiating between listed, unlisted, and incompatible drives, helping users understand the operational impact of their hardware choices before deploying them into active volumes or caches.

For professionals managing larger deployments, DSM 7.3 also provides expanded transparency on what Synology considers “verified reliability,” listing the precise categories of tests that certified drives undergo—thermal stress, power cycle endurance, and abnormal shutdown simulation—before being added to the official compatibility list. These details are especially relevant for IT administrators planning storage upgrades or migrations, as the new compatibility tables make it clear which drive types can be used in different Synology product families. This article breaks down the logic behind these changes, explains how Synology’s updated system reacts to various drive types, and clarifies which NAS lines now support third-party drives under DSM 7.3.

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Why Synology Has Changed Hard Drive and SSD Support in DSM 7.3?

When the Synology 2025 PLUS series launched in spring 2025, Synology’s decision to restrict many newer NAS models to officially approved Synology-branded drives marked a major turning point in the company’s storage policy, triggering widespread criticism across its user base. Systems like the DS923+ and DS1522+ suddenly required drives from Synology’s HAT or SAT ranges for creating new storage pools, leaving long-time users frustrated that they could no longer use trusted third-party disks from vendors such as Seagate or Western Digital. Synology’s explanation at the time centered on reliability: they claimed a growing number of support incidents were linked to unverified drives with unstable firmware, inconsistent temperature readings, or poor power recovery behavior. The aim was to unify performance standards across the portfolio and ensure that every supported configuration met enterprise-grade validation tests already used in their FS and SA lines. However, as the backlash grew throughout 2024 and early 2025, it became clear that many customers—especially small businesses and home users—felt alienated by this rigid policy. Some migrated to alternative NAS ecosystems, while others publicly voiced concerns about the long-term openness of Synology’s platform. In response, Synology developed a new compatibility framework known as HCL 5.0, introduced in DSM 7.3, to strike a balance between reliability and flexibility. This new approach reinstates the ability to use unlisted hard drives and 2.5-inch SATA SSDs for storage pool creation on 2025 DiskStation Plus, Value, and J series models, provided the drives are not explicitly marked as incompatible. Meanwhile, enterprise systems such as the FS, SA, XS, and HD ranges continue to enforce strict compatibility for mission-critical stability. Synology described this as a pragmatic evolution of its policy, aligning with customer expectations while continuing to collaborate with major drive manufacturers to validate additional models under its new testing program. The result is a hybrid policy that protects Synology’s enterprise reliability standards but restores much of the flexibility and user confidence that defined the brand’s earlier systems.

What Happens When a User Installs a Hard Drive That Is Not on the Compatibility List but Is Not on the Incompatibility List Either?

Under DSM 7.3, Synology has overhauled how its NAS systems handle drives that are not officially listed in the compatibility database but are also not explicitly marked as incompatible. This new policy, part of the HCL 5.0 framework, restores the flexibility that was largely lost with DSM 7.2. For users of 2025 DiskStation Plus models, including systems such as the DS1525+, DS925+, and DS725+, these drives are now treated as fully functional and supported for installation, storage pool creation, and volume management. When a non-listed HDD or SATA SSD is installed in these units, DSM 7.3 accepts it without generating warnings, restrictions, or “unverified” messages. The drive behaves identically to a fully approved model, and users can create new RAID arrays, expand existing volumes, and use all standard DSM features such as snapshots, encryption, and Hyper Backup. This marks a significant shift from DSM 7.2, which blocked pool creation entirely if the installed drive was not verified by Synology.

The only distinction that remains is on the support side rather than the user interface. While DSM 7.3 operates normally with these drives, Synology’s technical support team may limit assistance for issues proven to be caused by non-listed hardware. This distinction allows experienced users to use mixed or legacy drives at their discretion while maintaining a clear boundary of responsibility. From a practical standpoint, performance, drive telemetry, and reliability monitoring remain fully available, including S.M.A.R.T. analysis, temperature reporting, and bad sector scanning. Storage pools built with these drives are indistinguishable from those using Synology-validated models, which means users can freely upgrade or migrate without worrying about feature loss.

The only exceptions to this open policy involve M.2 NVMe drives and systems outside the Plus, Value, or J series. NVMe SSDs used for caching or storage pools still require official validation because they endure heavier sustained write loads and generate more heat under continuous NAS workloads. As a result, only listed M.2 models can be used for new cache or pool creation, though previously configured drives can still be migrated. Meanwhile, enterprise-oriented NAS lines such as the RS, FS, SA, and XS series continue to operate under stricter compatibility rules, where only officially listed drives can be used for new storage pool creation. In these systems, non-listed drives can sometimes be recognized for migration, but cannot participate in new arrays or cache volumes.

For most users, this means that DSM 7.3 on the 2025 Plus series finally restores the traditional Synology experience: the ability to use virtually any NAS-grade hard drive or 2.5-inch SSD without restriction. It also removes the previous generation’s unnecessary barriers that alienated long-term customers. Synology has positioned this change as a response to community feedback, reaffirming that flexibility can coexist with reliability. The HCL 5.0 framework is now the baseline for all new consumer and prosumer systems, signaling Synology’s partial return to an open and more user-friendly storage policy.

How Is Hard Drive Compatibility in DSM 7.3 on the Rackstation/RS and NVR/DVA Surveillance NAS Systems?

While the original restrictions are expected (though not wholy welcome) for enterprise-grade units, DSM 7.3 also applies similar limitations to rackmount Plus (RS+) and DVA/NVR models, which has generated frustration among users expecting parity with desktop Plus series devices. Systems such as the RS2423RP+, RS422+, and DVA1622 remain governed by a more conservative policy, where only drives on the compatibility list can be used for new pool creation, and unlisted HDDs are accepted only for migration. In contrast to the new, flexible policy introduced for 2025 DiskStation Plus models, these rackmount and surveillance systems do not yet benefit from the same relaxed rules. This distinction is particularly disappointing given that many surveillance-optimized HDDs—such as Seagate’s SkyHawk or IronWolf ranges—have not yet been verified by Synology for DVA or NVR units, leaving buyers with fewer officially supported choices despite these drives being purpose-built for similar workloads.

The DVA and NVR product lines further complicate matters because their operating environments rely heavily on consistent write performance and power management behavior. Synology’s internal reasoning is that drive validation for continuous surveillance recording requires more predictable I/O latency and lower error recovery times than typical NAS workloads. However, the practical impact is a reduced range of compatible disks, even when many third-party NAS or CCTV-specific drives are known to perform reliably under similar conditions. Until Synology expands its verification program to include these models, administrators deploying rackmount Plus or DVA systems must continue to rely exclusively on officially listed drives or accept limited migration-only functionality.

These restrictions highlight an ongoing inconsistency in Synology’s product ecosystem. DSM 7.3 offers broad flexibility and open drive use on desktop Plus series systems but maintains enterprise-grade rigidity across rackmount Plus and surveillance-focused models. For now, this gap means that users deploying DSM 7.3 on RS or DVA systems cannot benefit from the same simplified, user-friendly drive policy available to standard DiskStation Plus NAS units.

How Is Hard Drive Compatibility in DSM 7.3 on the FS, HD, SA, UC, XS+, XS, and DP Series?

In DSM 7.3, Synology continues to apply the most stringent validation rules across its enterprise and datacenter-class NAS platforms, which include the FS, HD, SA, UC, XS+, XS, RS, and DP series. These systems are built for environments where sustained uptime, predictable throughput, and long-term data integrity are non-negotiable. As a result, they rely entirely on Synology’s Enterprise Compatibility Framework, which only permits the use of drives that have been formally validated and listed on the official compatibility database. These listed drives undergo intensive reliability testing, including extended read/write stress cycles, multi-node redundancy simulations, and controlled recovery from power or network failures. DSM 7.3 enforces this framework to guarantee consistent behavior across RAID arrays and to ensure that firmware-level optimizations, such as error recovery timing and caching algorithms, work as designed with Synology’s proprietary storage stack.

For users of these enterprise models, drives fall into three possible states: listed, not listed, and incompatible. Listed drives are fully supported for installation, storage pool creation, caching, and migration. Drives that are not listed may still appear in Storage Manager but are limited to migration-only use, meaning they can be mounted if they come from an existing Synology system but cannot be initialized for new volumes or RAID groups. This allows data recovery or transition from legacy setups without granting full functionality. Meanwhile, drives on the incompatibility list are blocked entirely and cannot be used in any capacity. These restrictions are designed to prevent firmware mismatches or mechanical inconsistencies that could undermine array stability. In practice, this means that enterprise and rackmount models remain tied to the official drive ecosystem, often limited to Synology’s own HAT or HAS series drives or verified OEM equivalents.

In these product classes, DSM 7.3 also maintains a strict policy for cache and SSD usage. M.2 NVMe drives can only be used for caching or storage pools if they appear on the official compatibility list. Unlisted M.2 drives are detected by the system but cannot be assigned to any cache operation, even for testing purposes. Similarly, 2.5-inch SATA or SAS SSDs that are not verified cannot participate in new array creation, even though they may mount for migration. This conservative approach reflects Synology’s focus on maintaining data integrity over flexibility in its upper-tier systems, where downtime or data corruption can carry substantial business costs. DSM communicates these restrictions clearly during setup: any attempt to use an unsupported drive for new pool creation will trigger a warning explaining that the operation cannot proceed due to compatibility enforcement.

What are the benefits of Buying Synology-branded Hard Drives and SSDs?

In parallel with the policy adjustments introduced in DSM 7.3, Synology has also begun expanding a series of benefits and incentives aimed at customers who purchase Synology NAS systems together with Synology-branded storage media. These initiatives are part of the company’s ongoing effort to strengthen its vertically integrated ecosystem, ensuring optimal performance and reliability when all components come from the same source. In selected markets, buyers who purchase Synology HAT, HAS, or SAT series drives on the same invoice as their NAS hardware now receive extended warranty coverage of up to five years, administered directly through authorized distributors and resellers. In addition, Synology has introduced an Express Replacement program, allowing for immediate drive swaps during the warranty period without waiting for the defective unit to be shipped and inspected, effectively mirroring the convenience of a premium RMA service. These benefits are available at no extra cost when drives are purchased through approved channels. The initiative is designed to make Synology’s validated ecosystem more appealing to businesses seeking predictable lifecycle management and faster recovery in the event of hardware failure, while also providing an incentive for users to standardize on Synology-branded components rather than mixing third-party storage.

Head over to Blackvoid HERE to read Luka’s great write-up on DSM 7.3 below:

DSM 7.3 and Hard Drive / SSD Support Conclusion

DSM 7.3 might well represent the most comprehensive and transparent storage compatibility framework Synology has released to date (after years of obviscation and unclear messaging), but it also reinforces a clear divide between its consumer and enterprise platforms. The introduction of the HCL 5.0 policy marks a pragmatic shift from the heavily restricted DSM 7.1/7.2 model, restoring the flexibility that long-time users had relied on for more than a decade. On the 2025 DiskStation Plus series, users can once again install and operate any third-party NAS-grade HDD or SATA SSD without limitation, bringing back the open and adaptable system design that helped define Synology’s reputation. This balance between openness and validation shows the company’s recognition of user feedback and its effort to rebuild trust after widespread criticism of its earlier drive-locking policy. By maintaining full functionality for unlisted drives while still reserving strict validation for high-end hardware, DSM 7.3 offers a compromise that keeps consumer-grade systems practical and professional-grade systems predictable. Not ideal, but better than what was already in place.

However, DSM 7.3 also underlines the growing separation between Synology’s desktop Plus models and its rackmount Plus, DVA, and enterprise systems. While home and small-business users benefit from restored flexibility, administrators working with rackmount or surveillance solutions remain tied to tightly controlled drive lists. The continued exclusion of common NAS and NVR-grade drives—such as Seagate IronWolf and SkyHawk or WD Purple series—from the verified list limits adoption and drives up deployment costs, particularly for surveillance users who require high-capacity, continuous-write storage. Until Synology expands its validation program or aligns its rackmount Plus systems with the same drive-handling rules as its desktop equivalents, this divide will remain a sticking point. DSM 7.3 is therefore both a meaningful correction and a reminder that Synology’s storage policy continues to evolve in response to user pressure. It moves the platform back toward flexibility without abandoning its enterprise reliability philosophy, but the differences between product tiers are now more visible than ever.

Want to Support What We Do? Use the Links Below to Buy your NAS and/or HDD and SSD Media. Clicking these links will result in a small commission for anything you purchase, heading to me and Eddie @NASCompares and allows us to keep doing this! It’s just us two here and between this and ads, it’s the most passive way to keep us sailing! Thanks

Synology NAS and Media on Amazon – HERE Synology Products on B&H – HERE Seagate Ironwolf Media on Amazon – HERE WD Red Media on Amazon – HERE Seagate Products on B&H – HERE WD Products on B&H – HERE

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