Earlier, we touched upon disk groups and network requirements. Let's revisit them and add more context to how they impact the VSAN cluster.
Disk groups, as we defined earlier, are containers of a set ratio of SSDs to HDDs. Each disk group should have one SSD and a minimum of one HDD. The number of HDDs can be increased up to a maximum of seven per disk group. The aggregate of these disk groups from all the hosts in the cluster that contribute storage form a single large VSAN datastore. The composition of the disk group in particular plays a very important role in the performance outcome in a VSAN cluster.
SSDs contribute to performance and HDDs contribute to capacity. A higher ratio of SSD to HDD improves the performance, while the typical requirement is to have at least 10 percent SSDs. The role of SSDs is to accelerate the I/O throughput. The capacity of SSDs is split into two, 70 percent for read caching and 30 percent for write buffering.
Hence, if there is more...