Qnap’s TS-1886XU-RP is a NAS appliance with a secret. A glance at the front of this 2U rack mount appliance shows a standard set of 12 hot-swap LFF SATA drive bays but peek round the back and you’ll find two more cages each with three SFF bays.
This hybrid storage arrangement makes the TS-1886XU-RP highly versatile as you can dedicate the front bays to general storage duties and fit SATA SSDs in the rear bays and employ them for a range of caching services. Qnap’s QTS software offers two choices as they can be used as a general RAID-protected cache or as a performance tier for the Qtier 2 data migration feature.
The appliance is ready for some heavy-duty storage action as it’s powered by a quad-core 2.6GHz Intel Xeon D-1622 CPU partnered by 8GB of DDR4 ECC memory which can be boosted to a healthy 128GB. You can save some cash as Qnap offers a cheaper model with a base 4GB of memory but this will restrict the size of the SSD cache you can create.
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TS-1886XU-RP Hardware features
The appliance’s six SSD bays make it a great choice for running Qnap’s Qtier 2 data tiering app
The appliance offers plenty of port permutations as it presents quad Gigabit and the price includes Qnap’s dual-port 10GbE SFP+ PCI-E card. There’s room for more as three spare PCI-E slots are up for grabs and Qnap’s extensive compatibility list includes plenty of multi-Gigabit, 10GbE, 25GbE and 40GbE network adapters plus 16/32Gbps Fibre Channel (FC) cards.
Storage can be expanded hugely outside the box as the TS-1886XU-RP supports all of Qnap’s USB 3.2 tower and rack storage shelves or you can fit Qnap’s SAS3 expansion card and connect up to eight 12- or 16-bay SAS3 shelves. Power redundancy is present and correct as the price includes dual hot-plug 500W PSUs.
Internally, everything is nice and tidy with easy access to the expansion and memory slots for upgrades. Cooling is handled by three cold-swap fans behind the main drive backplane and noise levels are a little high with our iPad and SPLnFFT app measuring sound levels of 64dB from one meter in front.
Caching and tiering
The QTS SSD caching service makes big improvements to random write performance
For testing, we loaded up a triplet of 16TB Seagate IronWolf NAS drives and created a RAID5 array from the QTS Storage & Snapshots app. We also fitted four enterprise-class 1.92TB Micron 5200 Max SATA SSDs in the rear cages.
Standard SSD caches are easy to create from the same app where you choose your devices, opt for a read-only or read-write cache and decide whether to accelerate all I/O or only random operations. With multiple SSDs, you can choose mirrors, RAID5 or 6 arrays and if you have at least four SSDs, you can use a RAID10 mirrored stripe for the best performance.
The appliance’s memory limits the size of the cache as with our 8GB model, the maximum allowed cache size was 2TB which will be half that with the 4GB model. Also, the maximum cache size supported by QTS is 4TB and you’ll need to upgrade memory to at least 16GB to support this.
This isn’t a major issue as a 4TB cache will easily be enough for most SMBs but as you can’t specify the size of the cache there’s no benefit in using the latest high-capacity SSDs. To illustrate this on our system, we could create a mirrored read/write cache with two 1.92TB Micron SSDs but RAID10, 5 and 6 arrays were off the table.
Qtier 2 doesn’t have any SSD tier size limitations and it provides a wizard which identifies available SSDs, offers to create a high-performance tier and upgrades the storage pool on the fly. Data migration between tiers can be fully automated where the appliance monitors usage and migrates data during quiet periods.
It can also be controlled by applying a schedule and you can choose which tier new data should be first placed in. The new tiering on demand feature goes further as you can specify the volumes, NAS shares and LUNs you want it performed on and an SSD tier can be added, modified or removed on-demand.
Fibre channel and caching performance
The Hyper Data Protector beta app offers data protection services for virtualized environments
To test maximum performance, we installed a dual-port ATTO Celerity FC-322E 32Gbps FC adapter in the appliance. This model isn’t on Qnap’s compatibility list but it was accepted without any problems.
We also installed another ATTO Celerity 32Gbps FC adapter in a Dell PowerEdge T640 Xeon Scalable tower server and mapped a 1TB LUN to it. Using Iometer, we tested sequential and random read and write rates and I/O throughput for the same operations, first without caching and then with a dual SSD mirrored cache assigned to the storage pool.
As you can see from the graphs, caching provides no benefits for sequential and random read operations. Sequential write operations improved slightly but the biggest difference was with random writes as the cache boosted them by over 600%.
We saw the same overall impact with Iometer set to small 4KB blocks where sequential and random read throughput saw small improvements with caching. Again, sequential writes increased slightly while throughput for random writes settled at 62,100 IOPS – a massive 40-fold improvement.
QTS 4.4.2 on the TS-1886XU-RP
Qnap’s latest QTS 4.4.2 software has an even keener focus on backup features. Along with the excellent HBS (Hybrid Backup Sync) 3 app, Qnap now has the Hyper Data Protector (HDP) app in early beta testing which brings data protection to VMware and Hyper-V virtualized environments.
HDP loads a separate browser console where we used its wizard to add our Hyper-V host, create a repository on the appliance and set up a backup job for selected VMs. Jobs can be scheduled to run at regular intervals and set to encrypt all transmissions while repositories can have compression and deduplication applied.
Both G Suite and Office 365 now appear on Qnap’s radar as its new Boxafe app is designed to provide NAS-based data protection for these cloud services. This also opens a new browser console, where you add your domains, authenticate access and decide what components you want to back up.
Conclusion
The TS-1886XU-RP delivers a powerful hardware package for the price and its clever internal design makes it a perfect candidate for SSD-accelerated storage services. Its compact chassis offers plenty of expansion potential, Qnap’s QTS software delivers a great range of storage features and it performed exceptionally well in our fibre channel lab tests.
