Synology RS4021xs+ 16-Bay Rack NAS, Xeon D-1541, 16GB RAM, 10GbE, PCIe

The Synology RackStation RS4021xs+ 16-Bay NAS Enclosure is a high-performance, scalable storage solution designed for enterprise-grade environments requiring massive storage capacity, exceptional processing power, and advanced networking features. Powered by an Intel Xeon D-1541 8-core 2.1GHz processor and equipped with 16GB DDR4 ECC RAM (expandable), this NAS delivers reliable multitasking and fast data throughput.

Supporting 16 hot-swappable 3.5"/2.5" SATA drive bays, the RS4021xs+ offers extensive storage capacity with flexible RAID configurations, ensuring optimal data protection and performance. Featuring 2x 10GbE RJ45 ports and 4x Gigabit Ethernet ports for high-speed network connectivity and redundancy.

Equipped with 2 PCIe 3.0 x8 expansion slots, this rackmount NAS supports additional network cards or SSD cache adapters, enhancing storage efficiency and throughput. The redundant power supply ensures uninterrupted operation in critical deployments.

Powered by the intuitive Synology DiskStation Manager (DSM) operating system, the RS4021xs+ supports advanced storage management, data protection, backup, virtualization, and cloud integration features.

1. Intel Xeon D-1541 8-Core 2.1GHz processor for enterprise-level performance
2. 16GB DDR4 ECC RAM, expandable for intensive workloads
3. 16 hot-swappable SATA bays supporting RAID 0, 1, 5, 6, 10, and Synology Hybrid RAID (SHR)
4. Dual 10GbE RJ45 ports and 4 Gigabit Ethernet ports for fast and reliable networking
5. Two PCIe 3.0 x8 slots for expandability with SSD cache or 25GbE adapters
6. Redundant power supply for continuous uptime and reliability
7. Compatible with Synology DSM for seamless data management and backup

Ideal for demanding environments such as virtualization, large-scale data storage, backup, and disaster recovery, the Synology RS4021xs+ combines powerful hardware with flexible software to deliver enterprise-ready NAS performance.

Securing your business assets

The 16-bay RS4021xs+ provides solid data security and lightening-fast performance with over 234K 4K random read IOPS and 6,258 MB/s sequential read throughput¹. Together with its 8-core processor, ECC memory, advanced snapshot technology, and built-in 10GbE connectivity, the RS4021xs+ can support large multi-user environments while handling data-intensive workloads.

Compute

Intel^® Xeon^® D-1541 8-core 2.1 GHz

Networking

Built-in dual-port 10GbE

Memory

16 GB ECC DDR4 Up to 64 GB

Scalability

Up to 40 drive bays with RX1217RP/RX1217

Engineered for service continuity

The RS4021xs+ ensures mission-critical data is always available, enabling businesses to deliver the best results, even in the face of disaster.

Redundant power

Dual PSUs provide protection against a PSU failure or accidental cord removal while hot-swappable fans can be replaced without powering down the system.

Maximize service availability

Synology High Availability (SHA) pairs two identical units together creating an active-passive cluster with minute-level failover. 

Next-generation file system

Btrfs prevents data corruption and reduces maintenance overheads with advanced storage technologies and optimized snapshots.

Customize to your business

The RS4021xs+ includes two PCIe slots for performance, networking, and storage upgrades enabling it to adapt to any business environment.

Double bandwidth

Upgrade network bandwidth in minutes by 2x or more with Synology’s range of 10GbE NICs.SSD cache

Boost read/write IOPS by up to 16 times by enabling SSD cache with our Synology M.2 NVMe adapter cards and SNV3500 SSDs, or by installing one or more 2.5” SAT5200 SSDs.

Storage expansion

Quickly and easily scale up to 40 drives with two RX1217RP/RX1217 expansion units.

The ultimate backup solutions — license-free

Keep disaster at bay

Hyper Backup

A comprehensive backup and recovery solution for securing data stored on Synology servers. Backup data locally, to another Synology device, rsync server, or cloud-based storage such as Google Drive, Dropbox, S3-compatible destinations, and Synology C2. Deduplication, integrity checks, and incremental transfer technology reduce bandwidth and storage used. 

Snapshot Replication

Easily schedule flexible point-in-time backups of shared folders and iSCSI LUNs with an RPO as low as 5 minutes and recovery in seconds. Set up replication and failover to other Synology storage systems for fast RTOs and minimal service disruption.

Backup your entire IT infrastructure

Active Backup Suite

Enables administrators to easily backup the entire IT infrastructure to their NAS, including Windows & Linux workstations and servers, file servers, VMware and Hyper-V virtual machines, and Microsoft 365 and Google Workspace accounts. Backups benefit from deduplication, multiversioning, and optimizations to reduce bandwidth and storage used. 

Storage for virtualization

Synology iSCSI storage supports mainstream virtualization solutions with an easy management interface to enhance usability. VMware vSphere 6.5 and VAAI integration helps offload storage operations. Windows Offloaded Data Transfer (ODX) speeds up data transfer. OpenStack Cinder support turns your Synology NAS into a block-based storage component. Additionally, Synology Storage Console enables even more simplified storage provisioning and management options in VMware and Windows environments.

All-in-one surveillance solution

Synology Surveillance Station transforms the RS4021xs+ into a feature-packed Network Video Recorder solution. Support for up to 90 IP cameras and video analytics such as motion detection, no idle zone, foreign object detection, and anomaly detection cater to the most common surveillance scenarios. 

Secure and private

AES-256 encryption keeps locally-stored footage secure.

Access from anywhere, anytime

Access recordings and live streams whenever you want using a web browser, desktop client, or the DS cam mobile app.

Real-time alerts

Email, SMS, or push notifications alert you when incidents occur or predefined conditions are met.

Works best with Synology drives

Engineered to handle intensive 24/7 workloads, Synology drives consistently deliver top-grade performance.

HDD

Enterprise Series 3.5" SATA

SSD

Enterprise Series 2.5" SATAEnterprise Series M.2 NVMe

Powered by Synology DiskStation Manager