
QNAP ES1686dc R2
High Availability Enterprise NAS with Dual Active Controllers
Our Price: $14,999.00
Our Price: $13,999.00
Our Price: $11,999.00
Want to build a custom bundle? Contact us!
Click here to jump to more pricing!
Overview:
Ensure uninterrupted mission-critical business operations with the high-availability ES1686dc R2 NAS. With redundant controllers and power supplies, it minimizes downtime, allowing seamless component replacement without disruption, ensuring reliability and continuity for enterprises.






Available Models
- ES1686dc-R2-2123IT-64G-
Intel® Xeon® D-2123IT 4-core 2.20 GHz processor (burst up to 3.0 GHz) per controller, 64 GB RDIMM DDR4 ECC (4 x 16 GB) per controller
- ES1686dc-R2-2142IT-96G-
Intel® Xeon® D-2142IT 8-core 1.90 GHz processor (burst up to 3.0 GHz) per controller, 64 GB RDIMM DDR4 ECC (4 x 16 GB) per controller
- ES1686dc-R2-2142IT-128G-
Intel® Xeon® D-2142IT 8-core 1.90 GHz processor (burst up to 3.0 GHz) per controller, 64 GB RDIMM DDR4 ECC (4 x 16 GB) per controller
Dual active-active controllers
Dual active-active controllers provide supreme uptime and redundancy to ensure high availability.
NVRAM module
NVRAM reduces the risk of losing write cache data if unexpected power failure occurs.
QES operating system
Supports ZFS near-limitless snapshots, SnapSync, block-level data deduplication, and inline data compression.
Storage for virtualization
Supports VMware® vSphere®, Windows Server® and Citrix® XenServer® for storage virtualization.
10GbE SFP+ ports
Four 10GbE SFP+ ports (per controller) accelerate virtualization, large file sharing, and intensive data transfer.
PCIe Gen 3 slots
Two PCIe slots (per controller) allow for adding 10GbE/25GbE networking cards to increase application performance.
Features:
Active-Active architecture: 2 units in a single chassis
Note: It is recommended to create multiple storage pools and distribute their ownership between both controllers to leverage the strengths of the ES1686dc R2 active-active controller architecture. This allows simultaneous output from both controllers for better load balancing.

Active-Standby Architecture
If the active system fails, the standby system starts up and takes over processing.
- Requires purchasing two systems for HA, doubling the cost.
- Causes load imbalance as only the active system processes workloads.
- A power outage may lead to data loss.
- Network disconnection invalidates the HA architecture, rendering it ineffective.

Active-Active Architecture
Both systems are active simultaneously.
- Both controllers handle traffic, optimizing workload distribution.
- Copy-To-Flash protection safeguards data against power failure.
- Dual-path SAS interface ensures seamless connectivity.
- Efficient resource utilization, reducing computational waste.
- High-speed, uninterrupted, and high-availability storage service.
- Supports multiple communication protocols: SMB, NFS, and iSCSI.
Intel® Xeon® D processors bring high performance and efficiency
Powered by two Intel® Xeon® D processors, the ES1686dc R2 features a dual active-active controller architecture that provides failover/failback operations as the standby controller takes over if one controller breaks down.
CPU
Intel® Xeon® D-2142IT 8-core 1.90 GHz processor (burst up to 3.0 GHz) per controller.
Memory
64GB RDIMM DDR4 ECC (4 x 16 GB) per controller, up to 512GB (8 x 64GB).

SMB Sequential Throughout (10GbE x 8) | Read 5773 MB/s |
Write 2201 MB/s |
iSCSI Random 4K IOPS (10GbE x 8) | Read 254828 IOPS |
Write 178552 IOPS |
Tested in QNAP Labs. Figures may vary by environment.
Multi-level cache technology
Multi-tier caching
The ES1686dc R2 simultaneously supports main memory read cache (L1 ARC), SSD secondary read cache (L2 ARC), and memory write cache (ZFS Intent Log) to meet performance demands of various enterprise applications.
Expand main memory up to 512GB
Both controllers have eight RDIMM slots, allowing for up to 512GB memory.
Note: The main memory will retain 8GB for use by the write cache.
NVRAM
In the event of power failure, the system can write cache data from the battery-protected DRAM to M.2 SSD through Copy To Flash (C2F) to ensure that data is not lost.
To ensure write cache data safety, it is recommended to annually replace the BBU. QNAP provides one-year warranty for the BBU.
PCIe Gen 3 slots
The ES1686dc R2 provides two PCIe Gen 3 x8 slots per controller connected to the CPU, allowing you to add additional functionality to meet growing workload and business requirements.
Network Card
Supports up to 25GbE, boosting virtualization, media file transfer, or adding support for iSER for improved virtualization performance.
SAS Storage Expansion Card
With the QXP-820S-B3408 SAS storage expansion card, you can scale up the ES1686dc R2 with QNAP’s TL SAS expansion enclosures.

Petabyte-scale, dual-controller SAS storage expansion
Gain petabyte-scale storage capacity using the QNAP’s expansion enclosure. Dual-channel (dual-path) connections allow service continuity even if one node fails.
NAS hardware you can rely on





QES: ZFS-based OS designed for HA systems
The ES1686dc R2 uses the QES operating system, which is based on the simple and efficient FreeBSD kernel and the ZFS file system that is suitable for high-end enterprise applications.
What’s the difference between QES and QuTS hero?
QES | QuTS hero | |
---|---|---|
OS Kernel | FreeBSD | Linux |
File system | ZFS | ZFS |
CIFS/FTP/NFS/iSCSI | ||
End-to-end data integrity | ||
Max. snapshots | 65,536 | 65,536 |
Remote disaster backup and recovery | SnapSync | SnapSync |
Deduplication | ||
Real-time data compression | ||
Real-time data compaction | ||
Application consistency | Snapshot Agent VSS Hardware Provider |
Snapshot Agent VSS Hardware Provider |
App Center | ||
Supported QNAP NAS models | Dual-controller NAS models | Single-controller NAS models |
Self-healing ensures data integrity and reliability
Designed to ensure data integrity, the QES-based ES1686dc R2 uses end-to-end checksums to detect and correct silent data corruption caused by hardware defects, firmware bugs or metadata errors. If integrity violations are detected, QES automatically repairs the damage using data from the other mirror before the data is passed to applications.

Unleashed SSD potential – agile and cost-effective for the ultimate performance
QES 2.2 features QNAP’s exclusive Write Coalescing algorithm that further optimizes all-flash performance in ZFS, providing a highly cost-effective all-flash solution for enterprise data management and mission-critical services.

Write Coalescing
Transforms all random writes to sequential writes along with reduced I/O. This not only increases random write performance for all-flash environments, but also improves SSD lifespan.

Pool over-provisioning
Users can allocate additional over-provisioning for SSDs (from 1% to 60%) and Storage Pools (from 1% to 40%) for a constant performance boost of over 100%.
Deduplication and compression maximizes VDI storage performance
In VDI environments where there could be over 90% duplicate data from virtual desktop OS images and applications, the QES-powered ES1686dc R2 provides businesses with the most cost-effective remote virtual desktop platform and mission-critical information warehousing.

Inline data deduplication
Block-based data deduplication optimizes storage usage and significantly decreases storage capacity requirements.

Inline compression
Shrinks data to reduce storage I/O workloads for improved performance. In VDI, deduplicated virtual desktops are easily cached to achieve optimal virtual desktop performance.

Inline compaction
Especially helpful for increasing SSD storage utilization efficiency when highly repetitive data or massive small files (such as transaction logs of banks or e-commerce) are generated. It delivers higher cost efficiency of all-flash storage systems.
Real-time SnapSync ensures minimal RPO with real-time disaster recovery
Real-time SnapSync ensures that both the primary and secondary NAS maintain identical data. When data is written to the source, it is immediately written to the destination. If the primary NAS goes offline, IT staff can simply adjust the privilege settings of the secondary NAS to ensure continuous operations. SnapSync provides the strongest support for nonstop business operations and helps users to reduce the risk of data loss.


Business Continuity
Copy-on-write technology makes QES snapshot creation almost instantaneous without affecting ongoing data writes. SnapSync supports incremental backups, real-time deduplication, and compression. The source ES1686dc R2 performs deduplication before compressing the metadata to reduce synchronized data and save bandwidth.

VMware SRM
SnapSync supports VMware Site Recovery Manager (SRM) that offers enterprise-class remote backup and disaster recovery solutions for virtual applications. With the Storage Replication Adapter (SRA) for SRM, operation overheads of the ESXi® server can be offloaded to a QNAP NAS to accelerate and simplify virtual machine backup/restore.
Compatible with VMware, Microsoft and Citrix virtualization
The ES1686dc R2 supports VMware® vSphere®, Windows Server®, and Citrix XenServer® for flexible deployment and management in virtualization environments.

Reliable, high-performance storage for virtualization
The ES1686dc R2 supports block-based iSCSI LUN as a reliable, high-performance, and affordable storage solution for mainstream virtualization environments. It supports VMware® VAAI and Microsoft® ODX to increase performance by offloading server loading for ESXi server and Hyper-V respectively.
Supports iSER for Improved VM Performance
The ES1686dc R2 supports iSER, combining iSCSI and RDMA (Remote Direct Memory Access), which can bypass general network drivers, the socket layer, and to directly enter memory buffers of the server and storage. Response time is also reduced to ensure service quality of the NAS.
Build an affordable Fibre Channel SAN environment
Common Fibre Channel Storage Area Networks (SAN) devices are often costly. By installing QNAP dual-port 16Gb/32Gb Fibre Channel expansion cards in the ES1686dc R2, you have more budget-friendly options to add a NAS to a SAN environment. You can set a Fibre Channel Target using the iSCSI & Fibre Channel app. Moreover, the LUN Masking and Port Binding features provide an additional layer of data security.
5-year warranty as standard
The ES1686dc R2 is backed by a 5-year warranty at no extra cost – providing your business organization with greater peace of mind.
Hardware Specifications:
ES1686dc-R2-2142IT-128G | ES1686dc-R2-2142IT-96G | ES1686dc-R2-2123IT-64G | |
---|---|---|---|
CPU | Intel® Xeon® D-2142IT 8-core 1.90 GHz processor (burst up to 3.0 GHz) per controller | Intel® Xeon® D-2142IT 8-core 1.90 GHz processor (burst up to 3.0 GHz) per controller | Intel® Xeon® D-2123IT 4-core 2.20 GHz processor (burst up to 3.0 GHz) per controller |
CPU Architecture | 64-bit x86 | ||
Floating Point Unit | |||
Encryption Engine | (AES-NI) | (AES-NI) | (AES-NI) |
System Memory | 64 GB RDIMM DDR4 ECC (4 x 16 GB) per controller | 48 GB RDIMM DDR4 ECC (4 x 4 GB+4 x 8GB) per controller | 32 GB RDIMM DDR4 ECC (4x 8 GB) per controller |
Maximum Memory | 512 GB (8 x 64GB) | ||
Memory Slot | 8 x R-DIMM/LR-DIMM DDR4 IMPORTANT: You can only use one type of dual in-line memory module (DIMM) at a time. Do not use registered DIMM (RDIMM) with load-reduction DIMM (LRDIMM) memory. |
||
Flash Memory | 4GB (Dual boot OS protection) | ||
Drive Bay | 16 x 3.5-inch SAS 12Gb/s, backward-compatible to SAS 6Gb/s |
||
Drive Compatibility | 3.5-inch bays: 3.5-inch SAS hard disk drives 2.5-inch SAS hard disk drives 2.5-inch SAS solid state drives |
||
Hot-swappable | |||
SSD Cache Acceleration Support | Read cache only |
Read cache only |
Read cache only |
Cache for Copy To Flash (C2F) | 1 per each controller (64GB M.2 SSD) | ||
Gigabit Ethernet Port (RJ45) | 3 for each controller (assign one for remote management) | ||
10 Gigabit Ethernet Port | 4 x 10GbE SFP+ for each controller | ||
Wake on LAN (WOL) | |||
Jumbo Frame | |||
PCIe Slot | 2 per controller Slot 1: PCIe Gen 3 x8 (CPU) Slot 2: PCIe Gen 3 x8 (CPU) Card dimensions for PCIe slot 1~Slot 2:215 x 68.9 x 18.76 mm / 8.46 x 2.71 x 0.74 inches. Wider cards can be installed if the next PCIe slot will not be used. |
||
USB 3.2 Gen 1 port | 2 per each controller Note: The USB ports are for engineering purpose only. No external devices such as storage drives or UPS are supported. |
||
Form Factor | 3U Rackmount | ||
LED Indicators | System Power LED (Green): on/off System Status (Green/ Orange): in operation, system errors, low power, degraded RAID mode, memory failure, fan/power supply failure, system/disk temperature too high, storage pool reaching threshold value, system performing take-over, power supply unit unplugged LCD Status Display (Two-digit number): Status of JBOD connection |
||
Buttons | Power, Reset | ||
Dimensions (HxWxD) | 132 × 446.2 × 587.75 mm | ||
Weight (Net) | 30.22 kg | ||
Weight (Gross) | 34.92 kg | ||
Operating temperature | 0 - 40°C (32°F - 104°F) | ||
Storage Temperature | -20 - 70°C (-4°F - 158°F) | ||
Relative Humidity | 5-95% RH non-condensing, wet bulb: 27°C (80.6°F) | ||
Power Supply Unit | Redundant/ Hot Swap Power Vin:90~264VAC;700W | ||
Power Consumption: Operating Mode, Typical | 500.87 W Tested with drives fully populated. |
||
Fan | Hot-swappable fan module (60*60*38mm; 16000RPM/12v/2.8A x 3) | ||
System Warning | Buzzer | ||
Standard Warranty | 5 | ||
Max. Number of Concurrent Connections (CIFS) - with Max. Memory | 10,000 | ||
Safety Standard | FCC Class A (USA only) CE Mark ( EN55022 Class A, EN55024) EN60950 BSMI VCCI CB LVD |
Note: Use only QNAP memory modules to maintain system performance and stability. For NAS devices with more than one memory slot, use QNAP modules with identical specifications and refer to the hardware user manual to install compatible QNAP memory modules.
Warning: Using unsupported modules may degrade performance, cause errors, or prevent the operating system from starting.
QNAP reserves the right to replace partial parts or accessories if the original is no longer available from its manufacturer/supplier. Any replacement would be fully tested and verified to meet strict compatibility and stability guidelines and will deliver identical performance to the original.
The terms HDMI, HDMI High-Definition Multimedia Interface, HDMI trade dress and the HDMI Logos are trademarks or registered trademarks of HDMI Licensing Administrator, Inc.
Product images are for illustrative purposes only and may differ from the actual product. Due to differences in monitors, colors of products may also appear different to those shown on the site.
Designs and specifications are subject to change without notice.
Pricing Notes:
- Pricing and product availability subject to change without notice.
Our Price: $14,999.00
Our Price: $13,999.00
Our Price: $11,999.00
Want to build a custom bundle? Contact us!