Qsan XCubeSAN XS5326D review: Fast and affordable SANs

When Qsan launched the XCubeSAN range of hybrid Flash arrays a few years ago it claimed a world's first as the only one to offer a 2U 26-bay model. This still holds true today as no other vendor can match this density and Qsan's latest XCubeSAN XS5326D continues this tradition.

Qsan scores even more points as the XS5326D is far better value that anything the blue chips have to offer. You get a lot for your money as the sub-£9K base price includes dual controllers running in active/active mode for fully transparent failover, SAS3 HDD and SSD support and combined iSCSI and Fibre Channel (FC) services.

It also has a high capacity potential using the controller's dual integral SAS3 ports. Qsan offers four disk shelf models and the XS5326D supports a total of 546 drives so you could push capacity to a mind-boggling 16.7PB. 

SATA drives are supported but as these are single-ported, they can only be used in the XS5326S single controller model (which can be upgraded to dual controllers whenever you want). Either way, there's no vendor lock-in as you can install any storage devices on Qsan's compatibility list which includes all key manufacturers.

Qsan XCubeSAN XS5326D review: Hardware specifications

The XS5326D controllers are more powerful than those in the 12-bay XS3312D as instead of 2GHz Xeon D-1712TR CPUs, they are equipped with quad-core 2.4GHz D-1715TER chips (the XS5326D-8C version has 8-core CPUs). They also get twice as much base memory with 16GB of DDR4 ECC cache in each one that can be field-upgraded to 256GB.

Port choices are extensive as the controllers come with integral Gigabit management and quad 10GbE SFP+ iSCSI data ports. Two module slots per controller are available and Qsan offers dual RJ-45 10GbE iSCSI, quad 10GbE SFP+ iSCSI, dual or quad 16Gbps Fibre Channel (FC), dual 25GbE iSCSI and dual 32Gbps FC.

The hot-plug cooling modules each have two dual-rotor fans and look after the entire chassis and controllers. You can also specify optional cache protection modules which come with M.2 flash memory and super capacitor power modules and fit in dedicated bays above the 850W hot-plug PSUs. The upshot of this end-to-end redundancy is it allows Qsan to claim five 9s reliability

Qsan XCubeSAN XS5326D review: Easy installation

The XFinder app makes light work of initial installation as it discovers the array's management ports and provides a quick link to the XEVO web console. Qsan created this to manage its all-Flash and hybrid arrays and it's designed to be user-friendly and easy to deploy.

The console presents an informative status screen showing installed devices, storage usage and an overview of arrays, pools, volumes and hosts. The window to the right provides a set of graphs for real-time views of overall latency, IOPS and throughput. 

Qsan supplied our review system with a full house of 960GB Samsung PM1643a SAS3 SSDs and we used the storage wizard to create two RAID5 pools using equal numbers of drives and asked for a single volume in each one to be configured for us. Storage features impress as the extensive RAID options include all standard types along with enhanced EE arrays which offer faster rebuild times by adding more spare drives to a pool.

Qsan supplied our system with dual-port 32Gbps FC and quad-port 16Gbps FC modules in each controller and host mapping is a simple process as all FC connections are automatically discovered. A noteworthy feature is the controllers function in synchronous mode so hosts connected across both controllers have all redundant links active and optimised.

Qsan XCubeSAN XS5326D review: Snapshots and replication

Protection groups streamline snapshot management as you can add multiple volumes to one group and protect them all with a single schedule. These run snapshots on specific days as often as every 5 minutes and you can run them on-demand as well. 

The price includes facilities for local replication of a volume to another local storage pool or remotely to an external array and these can be included in the same protection groups that manage snapshots. Network bandwidth controls for remote replication are also provided with a choice of eight traffic shaping groups.

Accessed from the heart icon at the top of the web console, the QSLife service keeps you posted on SSD usage and remaining life. It provides details on the remaining life of each SSD, usage graphs for each one and has three alert levels so you'll always know when an SSD is reaching the end of its working life.

Qsan XCubeSAN XS5326D review: Top performance

For initial speed testing, we used a Dell PowerEdge T640 Xeon Scalable Windows server equipped with two QLogic dual-port 32Gbps FC adapters. With host mapping sorted, we easily created a quad 32Gbps MPIO link to a volume on our first RAID5 array 

Performance looks good as Iometer reported sequential read and write rates of 91.4Gbits/sec and 92.2Gbits/sec and random rates of 91.4Gbits/sec and 90.1Gbits/sec. Swapping to Iometer 4KB blocks returned random read and write I/O throughputs of 710,200 and 254,500 IOPS

We then added a Dell PowerEdge R660 equipped with an ATTO Celerity quad-port 16Gbps FC HBA. With Iometer running on both servers, we recorded cumulative sequential read and write rates of 131.4Gbits/sec and 121.4Gbits/sec. 

Qsan claims the XS5326D can deliver up to 20GB/sec and we see no reason why this can't be achieved as our cumulative read speed equated to 16.4GB/sec. Random read and write numbers are pretty good too, with Iometer returning 131.4Gbits/sec and 47Gbits/sec.

The XS5326D delivers a high throughput for random operations as we recorded cumulative read and write rates of 1.1 million and 280,200 IOPS. The XEVO web interface provides plenty of hardware performance statistics but the one we'd still like to see included is CPU utilisation.

Qsan XCubeSAN XS5326D review: Verdict

The XCubeSAN XS5326D will appeal to SMBs and enterprises alike as this hybrid Flash array is very competitively priced. It's easy to deploy and manage, delivers excellent performance and the transparent failover, end-to-end redundancy and five 9s reliability makes it ideal for hosting mission-critical storage.

Qsan XCubeSAN XS5326D specifications