EVS Concepts

IOPS

Number of read/write operations performed by an EVS disk per second.

Disk Types and Performance

Throughput

Amount of data read from and written into an EVS disk per second.

Read/write I/O latency

Minimum interval between two consecutive read/write operations of an EVS disk.

Burst capability

A small-capacity disk can surpass its official maximum IOPS for a short period of time.

VBD

A device type of EVS disks. VBD EVS disks only support basic SCSI read/write commands.

Device Types

SCSI

A device type of EVS disks. SCSI EVS disks support transparent SCSI command transmission and allow the server OS to directly access the underlying storage media.