Disk-intensive ECSs

Overview

• They use local disks to provide high sequential read/write performance and low latency, improving file read/write performance.
• They provide powerful and stable computing capabilities, ensuring efficient data processing.
• They provide high intranet performance, including high intranet bandwidth and packets per second (PPS), meeting requirements for data exchange between ECSs during peak hours.

Specifications

Notes on Using D6 ECSs

• If the host where a D6 ECS is deployed is faulty, the ECS cannot be restored through live migration.
  • If the host is faulty or subhealthy and needs to be repaired, you need to stop the ECS.
  • In case of system maintenance or hardware faults, the ECS will be redeployed (to ensure HA) and cold migrated to another host. The local disk data of the ECS will not be retained.
• D6 ECSs do not support specifications modification.
• D6 ECSs do not support local disk snapshots or backups.
• D6 ECSs can use both local disks and EVS disks to store data. Note the following when using the two types of storage media:
  • Only an EVS disk can be used as the system disk of a D6 ECS.
  • Both EVS disks and local disks can be used as data disks of a D6 ECS.
  • A maximum of 60 disks (including VBD, SCSI, and local disks) can be attached to a D6 ECS. Among the 60 disks, the maximum number of SCSI disks is 30, and the VBD disks (including the system disk) is 24. For details, see Can I Attach Multiple Disks to an ECS?
    Note

    The maximum number of disks attached to an existing D6 ECS remains unchanged.

• You can modify the fstab file to set automatic disk mounting at ECS start.
• The local disk data of a D6 ECS may be lost if an exception occurs, such as physical server breakdown or local disk damage. If your application does not use the data reliability architecture, it is a good practice to use EVS disks to build your ECS.
• When a D6 ECS is deleted, its local disk data will also be automatically deleted, which can take some time. As a result, a D6 ECS takes a longer time than other ECSs to be deleted. Back up the data before deleting such an ECS.
• Do not store service data in local disks for a long time. Instead, store it in EVS disks. To improve data security, use a high availability architecture and back up data in a timely manner.
• Local disks can only be purchased during D6 ECS creation. They cannot be separately purchased after the ECS has been created. The quantity and capacity of your local disks are determined according to the specifications of your ECS.

Notes on Using D3 ECSs

• If the host where a D3 ECS resides becomes faulty, the ECS cannot be restored through live migration.
  • If the host is faulty or subhealthy, you need to stop the ECS for hardware repair.
  • In case of system maintenance or hardware faults, the ECS will be redeployed (to ensure HA) and cold migrated to another host. The local disk data of the ECS will not be retained.
• D3 ECSs do not support specifications modification.
• D3 ECSs do not support local disk snapshots or backups.
• D3 ECSs can use both local disks and EVS disks to store data. In addition, they can have EVS disks attached to provide a larger storage size. Note the following when using the two types of storage media:
  • Only an EVS disk, not a local disk, can be used as the system disk of a D3 ECS.
  • Both EVS disks and local disks can be used as data disks of a D3 ECS.
  • A maximum of 60 disks (including VBD, SCSI, and local disks) can be attached to a D3 ECS. Among the 60 disks, the maximum number of SCSI disks is 30, and the VBD disks (including the system disk) is 24. For details, see Can I Attach Multiple Disks to an ECS?
    Note

    The maximum number of disks attached to an existing D3 ECS remains unchanged.

• You can modify the fstab file to set automatic disk mounting at ECS start.
• The local disk data of a D3 ECS may be lost if an exception occurs, such as physical server breakdown or local disk damage. If your application does not use the data reliability architecture, it is a good practice to use EVS disks to build your ECS.
• When a D3 ECS is deleted, its local disk data will also be automatically deleted, which can take some time. As a result, a D3 ECS takes a longer time than other ECSs to be deleted. Back up the data before deleting such an ECS.
• Do not store service data in local disks for a long time. Instead, store it in EVS disks. To improve data security, use a high availability architecture and back up data in a timely manner.
• Local disks can only be purchased during D3 ECS creation. The quantity and capacity of your local disks are determined according to the specifications of your ECS.

Application Scenario

• Applications: Massively parallel processing (MPP) database, MapReduce and Hadoop distributed computing, and big data computing
• Features: Suitable for applications that require large volumes of data to process, high I/O performance, and rapid data switching and processing.
• Application scenarios: Distributed file systems, network file systems, and logs and data processing applications