Synology RackStation RS4021xs+ Rackmount 3U 16-Bays (Expandable upto 40-Bays) – RS4021xs+

 

 

RackStation RS4021xs+

Enterprise NAS with built-in service continuity engineered for data-intensive applications.

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Overview

 

Features

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.

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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 RX1217(RP)

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. Learn more

Next-generation file system

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

 

Customize to your business

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

The ultimate backup solutions — license-free

 

Keep disaster at bay

Backup your entire IT infrastructure

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. Learn more

     

 

• M.2 SSD SNV3000

 

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.

 

Central Management System

Conveniently manage your fleet of Synology NAS from a centralized console.

Learn more

Synology Drive

Instantly access your NAS files across multiple devices whenever you want, wherever you are.

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Collaboration Suite

Satisfy all team collaboration needs behind the safety of your own private cloud with Synology Office, Calendar, and Chat.

Learn more

Virtual Machine Manager

Run various operating systems in isolated sandboxes. Seamlessly clone, store, and migrate virtual machines.

Learn more

Security

Shield your Synology NAS from the most sophisticated threats with industry-leading security solutions.

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Public Cloud Integration

Back up and synchronize data easily between public cloud accounts and your NAS.

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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

 

 

RackStation RS4021xs+

• 1 Power button and indicator
• 2 Alert Off Button
• 3 Drive tray
• 4 Drive status indicator

• 5 PSU fan
• 6 Power Port
• 7 PSU Indicators & Alert Off Buttons
• 8 Console port

• 9 1GbE/10GbE RJ-45 Ports
• 10 USB 3.2 Ports
• 11 Expansion port
• 12 PCIe expansion slot

• 13 Reset button

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Detailed Tech Specification

 

Hardware Specs

 

CPU	CPU Model	Intel Xeon D-1541
	CPU Quantity	1
	CPU Architecture	64-bit
	CPU Frequency	8-core 2.1 (base) / 2.7 (turbo) GHz
	Hardware Encryption Engine (AES-NI)	Yes
Memory	System Memory	16 GB DDR4 ECC UDIMM
	Memory Module Pre-installed	16 GB (16 GB x 1)
	Total Memory Slots	4
	Maximum Memory Capacity	64 GB (16 GB x 4)
	Notes	Synology reserves the right to replace memory modules with the same or higher frequency based on supplier’s product life cycle status. Rest assured that the compatibility and stability have been strictly verified with the same benchmark to ensure identical 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 more information about the recommended memory configurations, please check the Hardware Installation Guide of your Synology product.
Storage	Drive Bays	16
	Maximum Drive Bays with Expansion Unit	40 (RX1217/RX1217RP x 2)
	Compatible 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. “Compatible drive type” indicates drives that have been tested to be compatible with Synology products. This term does not indicate the maximum connection speed of each drive bay.
External Ports	RJ-45 1GbE LAN Port	4 (with Link Aggregation / Failover support)
	RJ-45 10GbE LAN Port	2 (with Link Aggregation / Failover support)
	USB 3.2 Gen 1 Port*	2
	Expansion Port	2
	Notes	The USB 3.0 standard was renamed to USB 3.2 Gen 1 by the USB Implementers Forum (USB-IF) in 2019.
PCIe	PCIe Expansion	2 x Gen3 x8 slots (x8 link)
File System	Internal Drives	Btrfs EXT4
	External Drives	Btrfs EXT4 EXT3 FAT NTFS HFS+ exFAT
	Notes	exFAT Access can be installed for free from Package Center in DSM 7.0. In DSM 6.2 or earlier versions, exFAT Access needs to be purchased in Package Center.
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 W 550 W
	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 W (Access) 62.68 W (HDD Hibernation)
	British Thermal Unit	497.14 BTU/hr (Access) 213.74 BTU/hr (HDD Hibernation)
	Notes	Power supply specifications may differ based on the hardware revision of the device. For more information, refer to the Product Change Notice. Power consumption is measured when it is fully loaded with Synology 8TB HAT5300-8T hard drive(s). 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)
	Relative Humidity	5% to 95% RH
Certification	FCC CE BSMI VCCI RCM EAC CCC KC UL
Warranty	5 Years
	Notes	The warranty period starts from the purchase date as stated on your purchase receipt. (Learn more)
Environment	RoHS Compliant
Packaging Content	Main Unit X 1 Accessory Pack X 1 AC Power Cord X 2 Quick Installation Guide X 1
Optional Accessories	DDR4 ECC UDIMM: D4EC-2666-16G Expansion Units: RX1217/RX1217RP 3.5″ SATA HDD: HAT5300 2.5″ SATA SSD: SAT5210 M.2 SSD & 10GbE Combo Adapter Card: E10M20-T1 M.2 SSD Adapter Card: M2D20 25GbE Network Interface Card: E25G21-F2 10GbE Network Interface Card: E10G21-F2/E10G18-T2/E10G18-T1 Rail Kit Sliding: RKS-02 VisualStation: VS360HD Surveillance Device License Pack
	Notes	All memory modules will operate at the maximum frequency specified by the CPU manufacturer.

 

Software Specs

 

DSM Specifications
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 (White Paper)	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	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. On Peta Volume enabled volumes, Snapshot Replication, SSD caching, shared folder encryption, and compression will not be available. Please refer to this article for more information on limitations. Actual maximum storage pool and volume sizes depend on drive sizes used, the number of drive bays available, and the RAID configuration. Each internal volume (may consist of multiple drives) is expandable up to 108 TB (with memory less than 32 GB) or 200 TB (with memory equal to or greater than 32 GB).
File Services	File Protocol	SMB/AFP/NFS/FTP/WebDAV
	Maximum Concurrent SMB/AFP/FTP Connections	4,000
	Maximum Concurrent SMB/AFP/FTP Connections (with RAM expansion)	10,000
	Windows Access Control List (ACL) Integration	Yes
	NFS Kerberos Authentication	Yes
	Notes	Regarding data concerning tests with RAM expansion, all memory slots are installed with the maximum capacity of supported RAM. During testing, the maximum number of SSDs supported by this model is installed in a RAID 5 configuration. The testing standard was based on the maximum number of concurrent connections supported by this model. During the testing, 25% of the connections were used to transfer files concurrently. The transfer process guaranteed that the connections were not interrupted; the minimum transfer speed was not guaranteed.
Account & Shared Folder	Maximum Local User Accounts	16,000
	Maximum Local Groups	512
	Maximum Shared Folder	512
	Maximum Shared Folder Sync Tasks	32
Hybrid Share	Maximum Hybrid Share Folders	15
	Notes	For more details about the maximum number of Hybrid Share folders, check this article.
High Availability	Synology High Availability	Yes
Log Center	Syslog Events per Second	3,000
Virtualization	VMware vSphere with VAAI	Yes
	Windows Server 2016	Yes
	Windows Server 2019	Yes
	Citrix Ready	Yes
	OpenStack	Yes
General Specifications	Networking Protocols	SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, Fibre Channel, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
	Supported Browsers	Google Chrome Firefox Microsoft 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.
Add-on Packages view the complete package list
Antivirus by McAfee (Trial)	Yes
Central Management System	Yes
Synology Chat	Maximum Users	6,000
	Maximum Number of Concurrent Users	500
	Notes	When applicable, systems are tested configured with maximum memory and set to allow the maximum number of connections.
Document Viewer	Yes
Download Station	Maximum Concurrent Download Tasks	80
SAN Manager	Maximum iSCSI Target Number	256
	Maximum LUN	512
	LUN Clone/Snapshot, Windows ODX	Yes
	Notes	iSCSI Manager has been renamed to SAN Manager in DSM 7.0.
Synology MailPlus / MailPlus Server	Free Email Accounts	5 (Licenses required for additional accounts)
	Maximum Number of Concurrent Users	1,100
	Maximum Server Performance	4,312,000 emails per day, approx. 131GB
	Notes	Models with more than 4 bays were installed with two SSDs for SSD cache. For tested models with expandable memory, the maximum amount of RAM was installed. The performance of the mail system will slightly decrease in high-availability mode due to data synchronization between the two servers. Functions that were enabled in all of the tests above: anti-spam, anti-virus, DNSBL, greylist, content scan, full-text search (English only).
Media Server	DLNA Compliance	Yes
Synology Photos	Facial Recognition	Yes
Snapshot Replication	Maximum Snapshots per Shared Folder	1,024
	Maximum of System Snapshots	65,536
Surveillance Station	Maximum IP cam (Licenses required)	90 (including 2 Free License) (see all supported IP cameras)
	Total FPS (H.264)	2700 FPS @ 720p (1280×720) 2250 FPS @ 1080p (1920×1080) 1500 FPS @ 3M (2048×1536) 900 FPS @ 5M (2591×1944) 550 FPS @ 4K (3840×2160)
	Total FPS (H.265)	2700 FPS @ 720p (1280×720) 2700 FPS @ 1080p (1920×1080) 2250 FPS @ 3M (2048×1536) 1500 FPS @ 5M (2591×1944) 1080 FPS @ 4K (3840×2160)
	Notes	Maximum IP cameras and FPS figures are tested with the device fully populated with drives and under a continuous recording setup. Actual system capabilities may differ depending on system configuration, drive performance, number of features enabled, and if additional workloads are present.
Synology Drive	Recommended Number of Concurrent Sync Clients	2,000 (the number of connections that can be maintained when the recommended number of hosted files was reached)
	Recommended Number of Hosted Files	50,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)
	Notes	Exceeding the recommended numbers above will not block application operations, but may result in longer response time. Utilizing SSD cache can significantly improve performance. For tested models with expandable memory, the maximum amount of RAM was installed. Btrfs file system and non-encrypted shared folders were used during the aforementioned testing.
Synology Office	Maximum Users	3,000
	Notes	Multiple files were opened for testing and each file was edited by 30 users simultaneously. For tested models with expandable memory, the maximum amount of RAM was installed. Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM
Video Station	Yes
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	60