is VMware vsphere storage connected to NFS or iSCSI?

VMware connects to shared storage in three different ways, San,ip sans (that is, iSCSI) and Nas (NFS). This article is not about the difference between the 3 and the SAN and NAS, please go to Google.

Second, this article does not look at FC Sans, if your environment already has a SAN that supports MPIO and has enough storage space, try to make the most of it. Because many articles point out that Nas/nfs is an ideal medium for low I/O demand workloads, fiber optics is ideal for high demand workloads. (Here is a reference to the translation: http://storage.chinabyte.com/387/8638887.shtml)

So, for VMware, is NFS good or iSCSI good? Many of the documents, including NetApp and VMware, are not exactly what they are. A more general statement is to see what kind of environment you are familiar with.

Cost

First, the most important factor that cannot be considered is cost. If you build a storage network from scratch, then the cost should be FC SAN > HW iscsi > SW iscsi = NFS. Here, we do not consider 10G Ethernet and FCoE. or because 10G of equipment and accessories are too expensive.

Real-World case: In our Organization's environment, because of cost considerations, there are no sans (san is usually more expensive, you have to buy a dedicated HBA card, at least 2 San Switch, and have FC San interfaces for your storage). Our internal storage network environment is mainly 2 kinds: iSCSI and NFS. Ms Cluster Service (such as email and Ms SQL) uses Iscsi,oracle DB for NFS. As a result, our vwware is left with 2 options, iSCSI and NFS. (iSCSI of hardware because CPU resources are not bottlenecks, throughput is not an advantage, due to cost considerations also give up)

Cost: SW ISCSI and NFS are tied.

Performance

NFS is ip-based, but not an ip-based storage protocol, and seems to be a bit more expensive in terms of network overhead. However, performance testing shows that NFS and iSCSI are almost equal (read performance is comparable, slightly poor write performance). (Reference document Http://www.vmware.com/files/pdf/perf_vsphere_storage_protocols.pdf)

Read performance: (Note that FC is a solo show because FC is 4gb/s bandwidth, while the other 3 are 1GB/S Gigabit Ethernet)

Write performance