Synology RackStation RS4021XS+ SAN/NAS Storage System

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 throughput. 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 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.

• 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 RX1217(RP) 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. Learn more

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. Learn more

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. Learn more

• Gigabit Ethernet
• 10 Gigabit Ethernet

• CIFS
• AFP
• NFS
• FTP
• WEBDAV
• SMB 1.0
• SMB 2.0
• SMB 3.0
• NFSv3
• NFSv4
• NFSv4.1
• iSCSI
• HTTP
• HTTPS
• SNMP
• LDAP
• CalDAV
• DLNA