Storage

ESXi abstracts physical storage from virtual machines by providing host-level storage virtualization. This additional virtualization level gives more flexibility and makes it possible to have storage-related features that are hard to implement with traditional physical servers.

For example, vSphere 5 introduced storage-related features such as:

• Storage vMotion: This allows migrating virtual machines between available storages without any downtime

• Storage Thin Provisioning: This improves space utilization by allocating available storage capacity between VMs dynamically

• Storage DRS: This provides load balancing between available storages based on I/O latency and storage capacity

• VMFS5: This is a high-performance filesystem optimized for VMs, and many more

Host storage adapters and storage configuration

The same way physical servers use disk controllers to access attached physical disks, VMs need virtual disc controllers to be able to use virtual disks. The following virtual SCSI controllers...