RackStation

RS4021xs+

Name: Synology RackStation RS4021XS+ 16-Bay 3U Diskless Scalable NAS Xeon CPU 16GB RAM
Brand: SYNOLOGY
SKU: RS4021XSPLUS
Price: 11844 AUD
Availability: InStock

Enterprise-grade rackstation storage solution

RS4021xs+ is backed by a 5-year limited warranty that includes technical support and hardware replacement services to maximize your return on investment.

Uncompromising performance

Throughput

2x 10GbE LAN ports

Scalability

Up to 40 drive bays with RX1217

CPU

8-core Intel Xeon D-1541 @ 2.1 (base) / 2.7 (turbo) GHz

Memory

16 GB DDR4 ECC UDIMM, expandable to 64 GB (16 GB x 4)

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.

All-in-one surveillance solution

Synology Surveillance Station transforms the RS4021xs+ into a feature-packed Network Video Recorder solution. Support for up to 285 IP camerasand video analytics such as motion detection, no idle zone, foreign object detection, and anomaly detection cater to the most common surveillance scenarios.Learn more

Works best with Synology drives

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

Powered by Synology DiskStation Manager

The RS4021xs+ runs Synology DiskStation Manager (DSM), the web-based operating system equipped with powerful applications and services for business.

5-year warranty

At Synology, we are committed to product innovation and quality. The RS4021xs+ is backed by a 5-year limited warranty that includes technical support and hardware replacement services to maximize your return on investment.Learn more

Powered by Synology DiskStation Manager

Enterprise-grade software solutions included

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.Learn more

Next-generation file system

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

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.

(RS4021XSPLUS)

Technical Specifications

Complete hardware and software specifications

CPU

CPU Model Intel Xeon D-1541

CPU Quantity 1

CPU Cores 8

CPU Threads 16

CPU Architecture 64-bit

CPU Frequency 2.1 (base) / 2.7 (turbo) GHz

Hardware Encryption Engine Yes

Memory

System Memory 16 GB DDR4 ECC UDIMM

Total Memory Slots 4

Maximum Memory Capacity 64 GB (16 GB x 4)

Notes Synology may revise pre-installed memory module specifications in response to component lifecycle and supply conditions. All revised components undergo the same rigorous validation to ensure equivalent compatibility, stability, and performance. Please select Synology memory modules for optimum compatibility and reliability. Synology will not provide complete product warranty or technical support if non-Synology memory modules are used for memory expansion. For multi-module memory configurations, all modules must be identical and share the same model number. Check the Product Manual of your Synology product for recommended memory configurations.

Storage

Drive Bays 16

Maximum Drive Bays with Expansion Unit 40 (RX1217 x 2)

Drive Type(See all supported drives) 3.5" SATA HDD 2.5" SATA SSD

Hot Swappable Drive* Yes

Notes Synology only guarantees full functionality, reliability, and performance for Synology drives listed on the compatibility list . The use of non-validated components may limit certain functionality and result in data loss and system instability.

External Ports

RJ-45 1GbE LAN Port 4

RJ-45 10GbE LAN Port 2

USB 3.2 Gen 1 Port 2

Expansion Port 2

Expansion Port Type Infiniband

PCIe

PCIe Expansion 2 x Gen3 x8 slots (x8 link)

Appearance

Form Factor (RU) 3U

Size (Height x Width x Depth) 132.3 mm x 482 mm x 656.5 mm

Weight 17.4 kg

Rack Installation Support* 4-post 19" rack (Synology Rail Kit - RKS-02 )

Notes The rail kit is sold separately

Others

System Fan 80 mm x 80 mm x 3 pcs

Fan Speed Mode Full-Speed Mode Cool Mode Quiet Mode

Easy Replacement System Fan Yes

Power Recovery Yes

Noise Level* 44.7 dB(A)

Scheduled Power On / Off Yes

Wake on LAN / WAN Yes

Power Supply Unit / Adapter 800 watts 550 watts*

Redundant Power Supply Yes

AC Input Power Voltage 100 V to 240 V AC

Power Frequency 50/60 Hz, Single Phase

Power Consumption 145.79 watts (Access) 62.68 watts (HDD Hibernation)

British Thermal Unit 497.14 BTU/hr (Access) 213.74 BTU/hr (HDD Hibernation)

Notes For more information on how power consumption is measured, refer to this article . Power supply specifications vary by hardware revision. An 800 W PSU is used in devices with serial numbers containing T2R (5th to 7th digits), while a 550 W PSU is in devices with ULR and VR4 serial numbers. For more information, refer to the Product Change Notice . Noise Level Testing Environment: Fully loaded with Seagate 2TB ST2000VN000 hard drive(s) in the idle state. Two G.R.A.S. Type 40AE microphones, each set up 1 meter away from the Synology NAS at the front and rear. Background noise: 16.49-17.51 dB(A); Temperature: 24.25-25.75˚C; Humidity: 58.2-61.8%

Temperature

Operating Temperature 0°C to 35°C (32°F to 95°F)

Storage Temperature -20°C to 60°C (-5°F to 140°F)

Operating Humidity 8% to 80% RH

Storage Humidity 5% to 95% RH

Certification

Certification FCC CE BSMI VCCI RCM EAC CCC KC BIS UL

Warranty

Warranty 5 Years

Notes The warranty period starts from the purchase date as stated on your purchase receipt. (Learn more)

Environment

Environment RoHS Compliant

Packaging Content

Packaging Content Main Unit X 1 Accessory Pack X 1 AC Power Cord X 2 Quick Installation Guide X 1

Optional Accessories

Optional Accessories DDR4 ECC UDIMM: D4EC-2666-16G Expansion Units: RX1217 / RX1217RP Enterprise Series 3.5" SATA HDD: HAT5300 Series Enterprise Series 2.5" SATA SSD: SAT5200 Series M.2 SSD & 10GbE Combo Adapter Card: E10M20-T1 M.2 SSD Adapter Card: M2D20 25GbE Network Interface Card: E25G30-F2 10GbE Network Interface Card: E10G30-F2 / E10G30-T2 / E10G18-T1 Rail Kit Sliding: RKS-02

Notes All memory modules will operate at the maximum frequency specified by the CPU manufacturer.

Storage Management

Maximum Single Volume Size 1 PB (64 GB memory required, for RAID 6 groups only) 200 TB (32 GB memory required) 108 TB

Maximum Internal Volume Number 256

SSD Read/Write Cache(Determining cache size) Yes

SSD TRIM Yes

RAID Group Yes

Supported RAID Type RAID F1 Basic JBOD RAID 0 RAID 1 RAID 5 RAID 6 RAID 10

RAID Migration Basic to RAID 1 Basic to RAID 5 RAID 1 to RAID 5 RAID 5 to RAID 6

Volume Expansion with Larger HDDs RAID F1 RAID 1 RAID 5 RAID 6 RAID 10

Volume Expansion by Adding a HDD RAID F1 JBOD RAID 5 RAID 6

Global Hot Spare Supported RAID Type RAID F1 RAID 1 RAID 5 RAID 6 RAID 10

Notes Volumes over 108 TB require 32 GB of memory or more. Actual maximum storage pool and volume sizes depend on drive sizes used, the number of drive bays available, and the RAID configuration. Usable capacity for each volume will be lower than the maximum volume size and is dependent on the filesystem and the amount of system metadata stored. When Peta Volume is enabled, validated services and packages are required. Please refer to this article for more information on limitations.

File System

Internal Drives Btrfs ext4

External Drives Btrfs ext4 ext3 FAT32 NTFS HFS+ exFAT

File Services

File Protocol SMB AFP NFS FTP WebDAV Rsync

Maximum Number of SMB Connections (FSCT-Based) 1,500

Windows Access Control List (ACL) Integration Yes

NFS Kerberos Authentication Yes

Notes Connection value of this model is tested with Synology SATA SSD fully populated and up to four 10GbE network ports Models with expandable memory are tested with the maximum supported quantity installed. SMB performance was evaluated using Microsoft File Server Capacity Tool (FSCT) version 1.3, with the following configuration: Test workload: HomeFolder scenario provided by the FSCT tool Test duration: 600 seconds Domain controller & FSCT controller: Windows Server 2022 FSCT clients: 8 × Windows 10 machines SMB feature: Directory leasing enabled

Account & Shared Folder

Maximum Local User Accounts 5,120

Maximum Local Groups 512

Maximum Shared Folder 512

Maximum Shared Folder Sync Tasks 32

Hybrid Share

Hybrid Share Folder Number 15

Hyper Backup

Data & Folder Backup Yes

Entire System Backup Yes

Notes Full-system backup requires DSM 7.2 or later.

High Availability

Synology High Availability Yes

Log Center

Syslog Events per Second 3,000

Virtualization

VMware vSphere ESXi 8.0 U2, ESXi 8.0 U1, ESXi 8.0, ESXi 7.0 U3, ESXi 7.0 U2, ESXi 7.0 U1, ESXi 7.0, ESXi 6.7 U3, ESXi 6.7 U2, ESXi 6.7 U1, ESXi 6.7, ESXi 6.5 U3, ESXi 6.5 U2, ESXi 6.5 U1, ESXi 6.5

Microsoft Hyper-V Windows Server 2022, Windows Server 2019, Windows Server 2016

Citrix XenServer XenServer 8, Citrix Hypervisor 8.2 LTSR CU1

OpenStack Cinder

General Specifications

Supported Protocols SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, Fibre Channel, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV

Supported Browsers Chrome Firefox Edge Safari

Supported Language English, Deutsch, Français, Italiano, Español, Dansk, Norsk, Svenska, Nederlands, Русский, Polski, Magyar, Português do Brasil, Português Europeu, Türkçe, Český, ภาษาไทย, 日本語, 한국어, 繁體中文, 简体中文

Notes For an updated list of supported browser versions, check the DSM Technical Specifications .

Central Management System

Central Management System Yes

Synology AI Console

Third-Party AI Model Integration Yes

Maximum De-Identification Rate 1,500 words per second

Notes De-identification performance measurement: Filters for Credit Card Numbers, IBAN, Individual Taxpayer Identification Number, SSN, and Names applied to a 4,355-word English text. To enable de-identification, your device must have at least 8 GB of memory and Container Manager installed.

Synology Chat

Maximum Number of Users 500

Notes Measured with simulated users, each with an average record of 20,000 messages, emojis, or stickers. The required server response time is below ten seconds. Models with expandable memory are tested with the maximum supported quantity installed.

Download Station

Maximum Concurrent Download Tasks 80

SAN Manager

Maximum iSCSI Target Number 128

Maximum LUN 256

LUN Clone/Snapshot, Windows ODX Yes

Synology MailPlus / MailPlus Server

Free Email Accounts 5 (Additional accounts require purchase of licenses)

Maximum Number of Users 3,200

Notes The suggested maximum number of users is based on the following workload: 20% of users with a 20,000 item mailbox randomly performing actions and receiving 240 emails per day, and 80% of users receiving 20 emails per day. Learn more Models with SSD support are tested with a single SSD volume. Models with expandable memory are tested with the maximum supported quantity installed. Learn more about memory requirements . Operating in high-availability mode will incur additional overhead. Features enabled during evaluation: anti-spam, anti-virus, DNSBL, greylist, content scanning, and full-text search (English).

Media Server

DLNA Compliance Yes

Synology Photos

Facial Recognition Yes

Object Recognition Yes

Snapshot Replication

Maximum Snapshots per Shared Folder 512

Maximum Snapshots per LUN 128

Maximum Snapshots per System 16,384

Maximum Replication Tasks for Shared Folders 64

Maximum Replication Tasks for LUNs 32

Maximum Replication Tasks per System 64

Surveillance Station

Default Licenses 2 (Additional cameras require purchase of licenses)

Maximum IP Cameras and Total FPS (H.264) 1080p: 280 channels, 2800 FPS 3M: 200 channels, 2000 FPS 5M: 120 channels, 1200 FPS 4K: 85 channels, 850 FPS

Maximum IP Cameras and Total FPS (H.265) 1080p: 285 channels, 8550 FPS 3M: 280 channels, 2800 FPS 5M: 200 channels, 2000 FPS 4K: 120 channels, 1200 FPS

Notes Surveillance Station 9.1.3 or above is required to support the maximum IP cameras and FPS figures listed. Performance figures are obtained from testing conducted with the device fully populated with drives, with their default memory configuration, and under a continuous recording setup. Actual system capabilities may vary based on configuration, drive performance, enabled features, and the presence of additional workloads. Use NVR Selector to quickly find a suitable model based on your requirements. The number of video channels that can be viewed simultaneously is double the maximum number of cameras for the same codec and resolution.

Synology Drive

Maximum Number of Users 2,700

Maximum Number of Hosted Files 25,000,000 (applies to files indexed or hosted by Synology Drive . For file access through other standard protocols, refer to the File Services section above)

Notes The suggested maximum number of users is based on the following workload: 20% of users randomly perform file operations (upload, download, move, and delete), and 80% of users are logged in but idle. Learn more Models with SSD support are tested with a single SSD volume. Models with expandable memory are tested with the maximum supported quantity installed. Exceeding the recommended numbers above will not block application operations, but may result in longer response time. Btrfs file system and non-encrypted shared folders were used during the aforementioned testing.

Synology Office

Maximum Number of Users 2,700

Notes The suggested maximum number of users is based on the following workload: 20% of users are executing random actions at an average of 30-second intervals, and 80% of users are logged in and viewing a file. Learn more Models with SSD support are tested with a single SSD volume. Models with expandable memory are tested with the maximum supported quantity installed. Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM

Virtual Machine Manager

Recommended Virtual Machine Instances 16 (Learn more)

Recommended Virtual DSM Number(Licenses required) 16 (including 1 Free License)

Notes The specifications vary depending on system configuration and memory size.

VPN Server

Maximum Connections 32

SKU	RS4021XSPLUS
Barcode #	846504004089
Brand	SYNOLOGY
Shipping Weight	17.4000kg
Shipping Width	0.630m
Shipping Height	0.890m
Shipping Length	0.310m