- Failing to use VCG-listed components, drivers and firmware, resulting in unpredictable behavior. Flash devices and IO controllers are particularly sensitive.
- Not properly sizing cache for capacity growth (e.g. thin volumes progressively getting fatter), resulting in declining performance over time.
- Using 1Gb networking for performance-intensive environments, with predictably poor results.
- Not understanding 3-node limitations associated with maintenance mode and protection after a failure.
- Using very large, slow disks for capacity, resulting in poor performance if an application is not cache-friendly.
- Failure to have sufficient extra capacity for operations.
This document focuses on the helping administrators to correctly design and size a Virtual SAN cluster, and answer some of the common questions around number of hosts, number of flash devices, number of magnetic disks, and detailed configuration questions to help to correctly and successfully deploy a Virtual SAN.