The EVS service offers scalable block storage for BMSs. With high reliability, high performance, and rich specifications, EVS disks can be used for distributed file systems, development and test environments, data warehouse applications, and high-performance computing (HPC) scenarios to meet diverse service requirements.
BMSs support EVS disks and are not subject to the capacity limit of local disks faced by traditional physical servers. In addition, shared EVS disks are supported. Multiple BMSs can access, read data from, and write data to a shared disk simultaneously, meeting your requirements for deploying core system clusters.
BMSs support the following types of EVS disks for storing data:
The key indicators of EVS disk performance include read/write I/O latency, IOPS, and throughput.
For details about EVS disk performance, see Elastic Volume Service User Guide.
The BMS only supports the Small Computer System Interface (SCSI) EVS disks.
You can create EVS disks for which Device Type is SCSI on the management console. These EVS disks support transparent SCSI command transmission, allowing BMS OS to directly access underlying storage media. Besides basic read/write SCSI commands, such EVS disks also support advanced SCSI commands.
The BMS public image OS is preinstalled with the driver required for using SCSI device type disks, and you do not need to install the driver explicitly. You can also learn how to install drivers in "Installing the SDI Card Driver" in Bare Metal Server Private Image Creation Guide.