Tripled SAS and SATA I-O performance – Nexsan’s claim for new FASTier NST5000 Series

Nexsan today launched the next generation of its FASTier storage systems, the NST5000 Series, including SSD cache and processing that it says triples random I-O performance for both SAS and SATA drives. With SAS previously producing three times SATA performance, an upgrade from SATA to SAS could bring nine times the previous data throughput.

Alternatively, as 7200 RPM SATA has five times the capacity of 15,000 RPM SAS (3TB versus 600 MB), an upgraded performance SATA drive could maintain SAS-level performance while multiplying capacity if that is the priority. SSD is also offered for further tier zero performance.

Total capacity in the three NST5000 models ranges from 8TB to over 1PB, and synchronous and asynchronous replication is supported. The NST5100 (8-93TB) uses a 4U high stand-alone unit, while Nexsan’s E60X modular 4U chassis housing 60 drives is used by the NST5300 (9-720TB in up to 4 units) and NST5500 (9-1080TB/1.08PB with 360 SATA drives in 6 units).

Its new “unified storage” capability optionally adds simultaneous support for iSCSI and NAS (CIFS/NFS) through one NAS head, also allowing a later upgrade for dedicated iSCSI or NAS users. Notably, fibre channel (FC) plays no part (whereas it is supported on the existing E5000 range); this may reflect the fact that Nexsan is primarily focused on the mid-market where there will be little FC interest going forward.

Nexsan’s feature-function-performance advance could stir the likes of EMC, Dell and NetApp to respond. For instance, Vicki Grey, Nexsan’s senior VP of marketing, emphasised a disk density advantage, with a 20U high NST5000 system yielding as much capacity as an EMC VNX5500 (22U), Dell EqualLogic (26U), NetApp FAS3240 (43U) or Dell Compellent (also 43U).

Not that these competitors are unaware of Nexsan. The company has now been growing quietly for nearly 13 years, and recently passed 10,000 customers (28,600 systems) across 60 countries. I know it is viewed as solid and reliable; Grey gave me the results of a large user survey which seemed to bear that out, showing a 96% satisfaction level.

So where does the huge random I-O throughput boost come from? It could not only be from caching. A big factor is surely that Nexsan now directs writes into a journal on DDR3 DRAM, from where the data is “drained” as it is applied to the storage. This technique, used by the biggest databases, was recently introduced by another storage vendor with similarly dramatic performance results in a virtualised environment.

Shared storage access through multiple VMs makes reading and writing a much more randomised operation, and disk latency can potentially cripple throughput. So I expect this sort of approach to become the norm before too long.

Grey explained that the high disk density also meant lower costs in cabling (also more reliable), DC floor space and energy usage (power and cooling). This will certainly attract administrators looking to boost performance but not costs.

A greatly expanded iSCSI feature set supports up to 64 iSCSI LUNs in a SAN accelerated by the FASTier cache – with thin provisioning and non-disruptive capacity upgrade while system is in use (no downtime) supported. Other features include application consistent snapshots for Windows servers (Microsoft VSS Hardware Provider), scheduled or manually-controlled snapshots for Linux and UNIX servers, and security features including LUN masking, CHAP and iSNS.

Other NST5000 configuration stats: 4-24 Intel Xeon cores, up to 12 dedicated RAID engines, 12-192GB DDR3 DRAM (running the operating system and the I-O cache), with FASTier main cache held on 16 SSDs on the SAS bus (up to 3TB) accessible by both controllers. US recommended pricing is also competitive – from $16,000 (NST5100), $87,000 (NST5300) and $111,000 (NST5500). Nexsan sells entirely through the channel.