ECSs support the following types of EVS disks for storing data:
High I/O (performance-optimized I) and ultra-high I/O (latency-optimized) EVS disks can be attached to SAP HANA or HL1 ECSs only.
EVS disks with different I/O capacities provide different features at different prices. Choose EVS disks based on your requirements. For more information about EVS disk specifications and performance, see Elastic Volume Service User Guide.
When you create an EVS disk on the management console, Device Type of the EVS disk is VBD by default. VBD EVS disks support only simple SCSI read/write commands.
You can create EVS disks for which Device Type is SCSI on the management console. These EVS disks support transparent SCSI command transmission, allowing ECS OS to directly access underlying storage media. SCSI EVS disks support both basic and advanced SCSI commands.
For more information about how to use SCSI EVS disks, such as installing a driver for a SCSI EVS disk, see FAQs > Do I Need to Install a Driver for EVS Disks with Device Type SCSI? in Elastic Volume Service User Guide.