Disk-intensive ECSs

Overview

D1 (disk-intensive first-generation) ECSs use local storage and provide high network performance. They are purpose-built for applications that require fast data processing and sequential read/write for ultra-large data sets in the local storage, such as distributed Hadoop computing and the processing of large volumes of concurrent data and logs.

Compared with D1 ECSs, D2 (disk-intensive second-generation) ECSs use local storage and provide high storage performance and internal bandwidth. They are applicable to distributed Hadoop computing, large data warehouse, distributed file system, and processing of logs and data.

NOTE:
  • Disk-intensive ECSs are in the beta test phase.
  • D1 ECSs have been discontinued. D2 ECSs that feature higher performance are available for new orders and capacity expansion for D1 ECSs.

Specifications

Table 1 Disk-intensive first-generation D1 ECS specifications

ECS Type

vCPUs

Memory (GB)

Flavor

Local Disks

Capacity of One Local Disk

Disk-intensive > First generation

4

32

d1.xlarge

3

1800 GB

8

64

d1.2xlarge

6

1800 GB

16

128

d1.4xlarge

12

1800 GB

36

256

d1.8xlarge

24

1800 GB

Table 2 Disk-intensive second-generation D2 ECS specifications

ECS Type

vCPUs

Memory (GB)

Flavor

Local Disks

Capacity of One Local Disk

Disk-intensive > Second generation

4

32

d2.xlarge.8

2

1800 GB

8

64

d2.2xlarge.8

4

1800 GB

16

128

d2.4xlarge.8

8

1800 GB

24

192

d2.6xlarge.8

12

1800 GB

32

256

d2.8xlarge.8

16

1800 GB

48

384

d2.12xlarge.8

24

1800 GB

Features of D2 ECSs

  • D2 ECSs use local disks to provide high sequential read/write performance and low latency, improving file read/write performance.
  • D2 ECSs provide powerful and stable computing capabilities, ensuring efficient data processing.
  • D2 ECSs with a CPU/memory ratio of 1:8 process large volumes of data.
  • D2 ECSs provide high internal network performance, including high internal bandwidth and packet per second (pps), meeting requirements for data exchange between ECSs during peak hours.

Notes on Using D1 ECSs

  • D1 ECSs do not support NIC hot swapping.
  • The primary and extended NICs of a D1 ECS have specified application scenarios. For details, see Table 3.
    Table 3 Application scenarios of the primary and extended NICs of a D1 ECS

    NIC Type

    Application Scenario

    Remarks

    Primary NIC

    Applies to vertical layer 3 communication.

    N/A

    Extended NIC

    Applies to horizontal layer 2 communication.

    To improve network performance, you can set the MTU of the extended NIC to 8888.

  • D1 ECSs do not support modifying specifications.
  • D1 ECSs do not support OS reinstallation or change.
  • D1 ECSs can use both local disks and EVS disks to store data. Use restrictions on the two types of storage media are as follows:
    • Only an EVS disk, not a local disk, can be used as the system disk of a D1 ECS.
    • Both an EVS disk and a local disk can be used as the data disk of a D1 ECS.
    • A D1 ECS can have up to 23 data disks (excluding local disks) attached.
      NOTE:

      The total number of EVS disks and NICs attached to an ECS is suggested not to be greater than 25. Otherwise, the attaching may fail.

  • The basic resources, including vCPUs, memory, and image, of a stopped D1 ECS are still charged. To stop charging such an ECS, delete it.

Notes on Using D2 ECSs

  • When the physical machine where a D2 ECS is deployed becomes faulty, the ECS cannot be migrated.
  • D2 ECSs do not support modifying specifications.
  • D2 ECSs do not support local disk snapshot or backup.
  • D2 ECSs do not support OS reinstallation or change.
  • D2 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. Use restrictions on the two types of storage media are as follows:
    • Only an EVS disk, not a local disk, can be used as the system disk of a D2 ECS.
    • Both an EVS disk and a local disk can be used as the data disk of a D2 ECS.
    • A D2 ECS can have up to 23 data disks (excluding local disks) attached.
      NOTE:

      The total number of EVS disks and NICs attached to an ECS is suggested not to be greater than 25. Otherwise, the attaching may fail.

  • The basic resources, including vCPUs, memory, and image, of a stopped D2 ECS are still charged. To stop charging such an ECS, delete it.
  • The local disk data of a D2 ECS may be lost due to some reasons, such as host machine breakdown or local disk damage. If your application does not use the data reliability architecture, you are strongly advised to use EVS disks to build your ECS.
  • When you delete a D2 ECS, the data on the local disk is automatically deleted.
  • Do not store service data for a long time in local disks. Instead, use EVS disks to store the data. In addition, back up data in a timely manner and use a high availability architecture.
  • You are not allowed to buy additional local disks. The quantity and capacity of your local disks are determined according to the specifications of your ECS. For D2 ECSs, if additional local disks are required, buy them when creating the ECSs.
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