Why is StarWind VSAN better than a SAN array?
There are many reasons for choosing Starwind vSAN over a physical SAN with an array:
- Performance: latency in arrays is higher due to accessing disks via network rather than locally, no caching.
- Redundancy: a SAN can be a single point of failure; if a SAN device fails, the entire environment fails.
- High availability: The SAN array with 2 controllers (quite expensive) operates in static active-active mode, unlike StarWind's which operates in true dynamic active-active mode.
- Scalability: Enterprise license guarantees support for unlimited capacity in HA mode, this license is not time-limited. This means you can increase/scale by adding disk shelves when all the bays/bays are already full, without additional software costs. In addition, it is usually necessary to replace SAN components after 3-5 years, while StarWind's license is perpetual.
- Managing 2 servers is easier, performance is better with locally available disks, and no dedicated network is required for storage. The customer can consolidate all its resources and storage, just on a few hosts. This will build an HCI (HyperConverged Infrastucture) infrastructure instead of separate servers and storage. This is more flexible and cost-effective. Buying a SAN for 3-10 TB of storage does not make sense. Even if large costs are not incurred, you will still have to buy a new device within 3-5 years. SAN with 10-20 TB makes sense, only for specific workloads (including high-performance databases). For 20+ TB, you may wonder about SAN deployment.
- Customers with storage up to 20 TB only need dedicated storage for backup. All their storage is on the same nodes as virtual machines (VMs) and applications.
Comparing SANs with 2 controllers and 1 set of drives
Comparing a SAN with 2 controllers and 1 set of disks with a typical StarWind configuration (2 or more nodes with dedicated storage) is not a comparison of equivalent configurations. It is more appropriate to compare 2 SANs with 2 StarWind nodes.
- A single SAN is a single point of failure: one set of disks is vulnerable to failure.
- Two controllers are a good solution, but some arrays have problems with firmware upgrades during operation. This situation means that two controllers may not be enough.
- Two SANs offering what StarWind VSAN has: active-active replication, fault tolerance, redundant DRAM for write cache purposes, RDMA protocol connections. When you add these functionalities, you will find that more expensive array solutions are required.
In summary, StarWind's 2-node system offers great fault tolerance, performance and functionality compared to a SAN with two controllers and one set of drives.
A SAN is more costly in the long run:
- It cannot be updated indefinitely. 2-3 years of updates are not a problem, but after 3-5 years vendors often stop publishing updates, thus forcing the customer to buy a new system.
- StarWind runs on regular x86 systems, which can be easily upgraded. The license is perpetual and can be transferred to new hardware if necessary. The market for used x86 systems is much larger than used SAN systems without technical support (support).
Proactive support and monitoring.
Cheap arrays do not offer such functionality.