A well established concept in the Network Attached Storage (NAS) market is Software Defined Storage (SDS). SDS is tailor-made for NAS, as a file system is, after all, a software construct and it should run on any hardware. While SDS is a natural fit in NAS, the hardware still matters, and it is necessary to optimize the software for the capabilities of that hardware, in order to obtain optimal results.
Why Hardware Matters
The first reason that hardware matters is more pragmatic than anything else. For most businesses, their product is not IT; IT is an enabler for their product. While these organizations may have IT staff, they do not want to nor have the time to do some of the more mundane IT tasks. For storage hardware that means ensuring all hardware and the drivers/firmware for the hardware are up to date and thoroughly tested and compatible with each other.
The second reason that hardware matters is more practical than anything else is. Software needs an engine. The engine should be designed with different enterprise workloads in mind to strike the perfect balance of performance, storage capacity, and price in one unified storage solution. That engine is CPU power/technology as well as storage type, capacity, and performance. The organization can use NAS for multiple use cases, ranging from hosting VMware virtual machines to being a backup target. An organization will often buy a NAS system from different vendors based on the use case. SDS on NAS allows the vendor to have greater hardware flexibility but continue to use the same software. The customer may purchase several hardware platforms for the different use cases but can manage it all from a common software platform.
Introducing the iXsystems TrueNAS M-Series
iXsystems is the primary developer of the open source project FreeNAS, but enterprises require more robust features, enterprise support, and prefer turnkey appliances. TrueNAS is iXsystems’ answer to that demand. The company has thousands of customers using the product for a variety of use cases, including as a unified (SAN/NAS) storage platform, as a backup storage target and as an object storage solution. It is built on the OpenZFS file system, which provides self-healing, ransomware protection as well as snapshot, replication, and encryption features.
The TrueNAS M-Series is built around Intel Xeon Scalable Family Processors to improve performance. It leverages a 12GB/sec SAS fabric, for drive interconnect, which reduces latency. It supports dual ported NVMe SSD and NVDIMM technologies to support data availability in case of a fail-over or maintenance event and to meet the most IOPS demanding workloads. Each TrueNAS M-Series unit includes dual active 10GbE storage connectivity and supports up to 25, 40, 50 and 100Gb/s Ethernet and 32Gb fibre channel networking.
The M-Series today consists of two models; the M40 and the M50. Both systems are 4U form factor. The M40 supports 23 drives and can expand with (2) 60 drive expansion shelves. The M50 can expand with up to (12) 60 drive expansion shelves. In a capacity-focused configuration, the M40 can deliver 2PB and the M50 can provide over 10 PB of raw capacity.
Beyond expansion capability, the fundamental difference between the units is their cache. The M40 uses dual-ported 12Gbps SAS SSDs for the read cache and NVDIMM for the write cache. The M50 uses dual ported NVMe for its read cache and NVDIMMs for the write cache. As a true enterprise storage platform, the TrueNAS M50 supports very demanding performance workloads with up to four active 100GbE ports, 3TB of RAM, 32GB of NVDIMM write cache and up to 15TB of NVMe flash read cache. Both systems have an active-standby controller architecture, which provides both redundancy and a guarantee of consistent performance in the failed state as well as support of ALUA for iSCSI and Fibre Channel protocols.
NAS is the storage workhorse of the data center. They are easy to set up, easy to connect and are flexible in most use cases. SDS on NAS increases that flexibility. However, NAS flexibility eventually leads to a challenge; they can’t scale to meet the demands of the data center. Some vendors have tried to resolve this challenge by creating scale-out NAS infrastructures but the problem is that these designs add complexity while limiting hardware and workload flexibility. iXsystems’ approach is to create a scale-up architecture with more raw capacity than most data centers will need and with a complimentary feature set that will ensure consistent performance as the organization leverages the NAS for more use cases.