Disk-intensive ECSs

Overview

D2 ECSs are developed based on KVM virtualization. They use local storage and provide high storage performance and intranet bandwidth for distributed Hadoop computing, large data warehouse, distributed file system, and log/data processing.

Specifications

Scenarios

• Applications

  Disk-intensive ECSs are suitable for applications that require large volumes of data to process, high I/O performance, and rapid data switching and processing.

• Application scenarios

  Big data computing, network file systems, data processing, MapReduce, Hadoop, and data-intensive computing

D2 ECS Features

• 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 vCPU/memory ratio of 1:8 process large volumes of data.
• D2 ECSs provide high intranet performance, including high intranet bandwidth and packets per second (PPS), meeting requirements for data exchange between ECSs during peak hours.
• Each D2 ECS supports a maximum configuration of 24 local disks, 60 vCPUs, and 540 GiB memory.

Notes

• Table 3 lists the OSs supported by disk-intensive ECSs.

  Table 3 Supported OS versions

  OS	Version
  Alma	Alma 8 64bit
  CentOS	CentOS Stream 8.6 64bit CentOS 7.9 64bit CentOS 7.7 64bit
  Debian	Debian GNU/Linux 11 64bit Debian GNU/Linux 10 64bit
  EulerOS	EulerOS 2.5 64bit
  Fedora	Fedora 35 64bit Fedora 34 64bit Fedora 33 64bit
  OpenSUSE	OpenSUSE 15.3 64bit
  Oracle Linux	Oracle Linux Server release 8.4 64bit Oracle Linux Server release 7.6 64bit
  Red Hat	Red Hat Enterprise Linux 7.9 64bit Red Hat Enterprise Linux 6.10 64bit
  Rocky	Rocky 8 64bit
  SUSE	Novell SUSE Linux Enterprise Server 15 SP3 64bit Novell SUSE Linux Enterprise Server 15 SP2 64bit Novell SUSE Linux Enterprise Server 15 SP1 64bit Novell SUSE Linux Enterprise Server 15 64bit Novell SUSE Linux Enterprise Server 12 SP5 64bit Novell SUSE Linux Enterprise Server 12 SP4 64bit Novell SUSE Linux Enterprise Server 12 SP3 64bit
  Ubuntu	Ubuntu 20.04 server 64bit Ubuntu 18.04 server 64bit
  Windows	Windows Server 2019 Standard 64bit Windows Server 2016 Standard 64bit Windows Server 2012 R2 Standard 64bit
  openEuler	openEuler 20.03 64bit

• If the host where a D2 ECS is deployed becomes faulty, the ECS cannot be migrated.
• To improve network performance, you can set the NIC MTU of a D2 ECS to 8888.
• D2 ECSs do not support specifications modification.
• D2 ECSs do not support local disk snapshots or backups.
• 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 EVS disks and local disks can be used as data disks of a D2 ECS.
  • A maximum of 60 disks (including VBD, SCSI, and local disks) can be attached to a D2 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?
    

    The maximum number of disks attached to an existing D2 ECS remains unchanged.

  • You are advised to use World Wide Names (WWNs), but not drive letters, in applications to perform operations on local disks to prevent drive letter drift (low probability) on Linux. Take local disk attachment as an example:

    If the local disk WWN is wwn-0x50014ee2b14249f6, run the mount /dev/disk/by-id/wwn-0x50014ee2b14249f6 command.

    

    How can I view the local disk WWN?

    1. Log in to the ECS.
    2. Run the following command:

       ll /dev/disk/by-id

• The local disk data of a D2 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 D2 ECS is deleted, its local disk data will also be automatically deleted, which can take some time. As a result, a D2 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 ECS creation. The quantity and capacity of your local disks are determined according to the specifications of your ECS.