Performance and scalability, all-in-one storage solution
Synology DS1821+ is tailor-made for IT enthusiasts and small and medium-sized enterprises, combining high performance and high scalability. The powerful computing power and transmission rate can meet high workloads, and combined with enterprise-level backup solutions, it can protect user data security.
AMD Ryzen ™
Quad-core 2.2 GHz processor
Dual M.2 2280 SSD slots, supports NVMe cache
4K random read up to 113,000 IOPS 1
With two DX517, it can be expanded to 18 hard drives.
The DS1821+ is designed to accelerate workloads, helping you reduce transfer times. Easily add faster networks and NVMe hard drive further improves performance.
Up to 2,322/1,460 MB/s read/write performance2
Up to 25GbE network3
2 x M.2 NVMe cache and storage pool 4
Take advantage of high-performance network and file access features without taking up unnecessary space. DS1821+ is equipped with 8 hard drive bays, but as data requirements increase, it can be expanded to 18 hard drive bays using 2 DX517 expansion units. 5
5 slots 15 slots
108 TB 252 TB
Synology iSCSI storage solutions fully support mainstream virtualization application environments and improve work efficiency through easy-to-use management interfaces. The integration of VMware vSphere 6 and VAAI can offload specific storage operations and optimize computing performance. Windows Offloaded Data Transfer (ODX) greatly improves data transmission and migration efficiency. OpenStack Cinder support can also configure your Synology NAS as a block-segmented storage component.
DS1821+ combines various backup applications to provide an intuitive user interface and reliable storage technology to protect your important data on all devices.
Centrally manage backup tasks for VMware, Windows and file servers. When necessary, quickly and reliably restore the services you need.
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Completely back up your files to local shared folders, external devices, another Synology NAS, rsync server, or public cloud to ensure data security.
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Protect your computer with Synology Drive Client. Easily perform instant backup and restore files at any point in time.
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Protect corporate data stored in the cloud. Manage local backup solutions from a centralized panel. Optimize storage performance with single-instance storage and block-level data deduplication technology.
Microsoft 365 Google Workspace
DS1821+ is specially designed to provide reliable data storage services and comes with Synology's three-year hardware warranty. Customers in some regions can also purchase a two-year extended warranty, giving them peace of mind for five years of use.
Manage multiple Synology NAS simultaneously through a centralized interface to improve management efficiency and flexibility.
Create a secure and reliable private email server with an intuitive user interface designed with style.
In the event of a server failure, data can be reliably transferred between clustered servers with minimal impact on applications.
Comprehensive built-in security tools are constantly updated to protect your device from ever-changing threats.
Provide a complete home monitoring solution to meet your recording and monitoring needs.
Synology hard drives are designed for intensive workloads, delivering long-term, stable and consistent performance.
This performance test data was tested in Synology's lab using efficient network configuration and system settings. Test results may vary under different environments. The performance data compared to the previous generation 8-slot model DS1819+. For complete test environment details, please refer to the Synology Transmission Performance page here .
Performance data is the result of SMB sequential transfer performance testing using Windows Server 2016 Datacenter on DS1821+ with Synology 10GbE NIC and SSD. Actual data may vary depending on testing environment, usage and settings. See the transmission performance chart for details.
PCIe expansion cards, expansion units, and storage drives are purchased separately. For information on compatible devices, see the compatibility list .
Synology SNV3400 series M.2 NVMe SSD hard drives can be installed through the built-in M.2 slot to enable SSD caching or create SSD storage pools. The hard drive needs to be purchased separately.
Storage capacity figures are calculated using RAID 5 configuration. Total storage capacity may vary depending on hard drive and RAID configuration used.
