NexGen boss: If solid hardness isn't stuck into PCIe - forget it

The John Spiers interview

El Reg: How do apps in servers use Nexgen storage resources?

NexGen CEO and co-founder John Spiers

John Spiers: All applications connect to NexGen shared storage resources via iSCSI. NexGen storage allows customers to set performance quality of service (QoS) levels to guarantee application performance from the storage system’s perspective along with performance service levels that allow users to prioritize application workload in degraded mode operation.

The data placement algorithms make evict/promote decisions to ensure the most active data stays in solid state while cold data is stored in the disk tier. Most other tiering solutions perform what we call "after the fact" data tiering where blocks are moved during slow periods based on historical workload statistics, whereas NexGen’s tiering is more like cruise control in a car, performance is delivered on-the-fly based on instantaneous demand, and tiering can also be scheduled to achieve a higher service level at a predetermined time; e.g.; during a VDI boot storm.

El Reg: How is Nexgen positioned against Nimble Storage?

John Spiers: We don’t see Nimble targeting the ability to manage and provision performance, and their system also consumes disk drive slots with solid state drives, which means they are using SSD behind a disk controller that has the issues highlighted above. We’ve also heard (but not confirmed) that they are using standard off the shelf LZ compression whereas we’ve designed our own data reduction technology specifically for a primary storage system to ensure no impact on application performance.

It never makes sense to implement solid state in a disk drive chassis behind a storage controller

El Reg: How is Nexgen Storage positioned versus Violin Memory?

John Spiers: We’re targeting the mid-range storage market, heterogeneous (virtual and physical servers, multiple OSes) application environments. This requires focusing on driving down $/GB, $/IOP, and footprint all at the same time.

We don’t see Violin focused on driving down $/GB and increasing capacity density, they seem to be targeting applications that require extreme performance. That being said, NexGen is compatible with Violin’s Solid State arrays that have a PCIe interface, so we view them as a potential partner.

El Reg: How should servers use SSD?

John Spiers: It depends on application need and customer budget.

If the applications don’t require storage high availability (HA) outside of the server, and more performance for the application justifies the cost, it makes sense to implement PCIe solid state in the servers. If the applications require storage HA, or the additional performance boost may not justify purchasing solid state for every server, then it makes sense to implement PCIe solid state in a shared storage system.

It never makes sense to implement solid state in a disk drive chassis behind a storage controller, as that implementation imposes bottlenecks on solid state performance which reduces the value. NexGen believes the SAN/NAS (shared storage) approach is more cost effective than the DAS approach for most mid-range storage customers.