Disk-intensive ECSs

Overview

Disk-intensive ECSs are delivered with local disks for high storage bandwidth and IOPS. Disk-intensive ECSs have the following features:

• 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.

D6 ECSs, with a vCPU/memory ratio of 1:4, use 2nd Generation Intel® Xeon® Scalable processors to offer powerful and stable computing performance. Equipped with proprietary 25GE high-speed intelligent NICs and local SATA disks, D6 ECSs offer ultra-high network bandwidth, PPS, and local storage. The capacity of a single SATA disk is up to 7.4 TB, and an ECS can have up to 36 such disks attached.

D3 ECSs use Intel® Xeon® Scalable processors to offer powerful and stable computing performance. Equipped with proprietary 25GE high-speed intelligent NICs and local SAS disks, D3 ECSs offer ultra-high network bandwidth, PPS, and local storage.

D2 ECSs are KVM-based. They use local storage for high storage performance and intranet bandwidth.

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

Specifications

Performance of a Single SATA HDD Disk Attached to a D6 ECS

Specifications of a Single SAS HDD Disk Attached to a D3 ECS

Specifications of a Single SAS HDD Disk Attached to a D2 ECS

Notes on Using D6 ECSs

• Currently, the following operating systems are supported (subject to the information displayed on the console):
  • CentOS 6.8/6.9/7.2/7.3/7.4/7.5/7.6/7.7/7.8/7.9 64bit
  • SUSE Enterprise Linux Server 11 SP3/SP4 64bit
  • SUSE Enterprise Linux Server 12 SP1/SP2/SP3/SP4 64bit
  • Red Hat Enterprise Linux 6.4/6.5/6.6/6.7/6.8/6.9/6.10/7.0/7.1/7.2/7.3/7.4/7.5/7.6/8.0 64bit
  • Windows Server 2008 R2 Enterprise 64bit
  • Windows Server 2012 R2 Standard 64bit
  • Windows Server 2016 Standard 64bit
  • Debian 8.1.0/8.2.0/8.4.0/8.5.0/8.6.0/8.7.0/8.8.0/9.0.0 64bit
  • EulerOS 2.2/2.3/2.5/2.9 64bit
  • Fedora 22/23/24/25/26/27/28 64bit
  • OpenSUSE 13.2/15.0/15.1/42.2/42.3 64bit
  • Ubuntu 20.04 64bit
• 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, not a local 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?
    

    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 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

• Currently, the following operating systems are supported (subject to the information displayed on the console):
  • CentOS 6.8/6.9/7.2/7.3/7.4/7.5/7.6/7.7/7.8/7.9 64bit
  • Red Hat Enterprise Linux 6.9/7.4/7.5/7.7/7.8/8.2 64bit
  • Windows Server 2008 R2 Enterprise 64bit
  • Windows Server 2012 R2 Standard 64bit
  • Windows Server 2016 Standard 64bit
  • Windows 10 Enterprise 64bit
  • Windows Server 1709 64bit
  • Windows Server 1909/2004 SAC 64bit
  • Windows Server 2012 R2 Datacenter 64bit
  • Windows Server 2012 R2 Standard 64bit
  • Windows Server 2016/2019 Standard 64bit
  • SUSE Enterprise Linux Server 12/15 64bit
  • Debian 8.6/8.10/9.0/10 64bit
  • EulerOS 2.5 64bit
  • Fedora 27/28 64bit
  • CoreOS 1298.6 64bit
  • Oracle Linux 6.9/7.3/7.4/7.5 64bit
  • Ubuntu 14.04/16.04/18.04/20.04 64bit
• 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. 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 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?
    

    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 ECS creation. The quantity and capacity of your local disks are determined according to the specifications of your ECS.

Notes on Using D2 ECSs

• Currently, the following operating systems are supported (subject to the information displayed on the console):
  • CentOS 6.8/6.9/7.2/7.3/7.4/7.5/7.6/7.7/7.8/7.9 64bit
  • Red Hat Enterprise Linux 6.9/7.4/7.5/7.7/7.8/8.2 64bit
  • Windows 10 Enterprise 64bit
  • Windows Server 1709 64bit
  • Windows Server 1909/2004 SAC 64bit
  • Windows Server 2012 R2 Datacenter 64bit
  • Windows Server 2012 R2 Standard 64bit
  • Windows Server 2016/2019 Standard 64bit
  • SUSE Enterprise Linux Server 12/15 64bit
  • Debian 8.6/8.10/9.0/10 64bit
  • Fedora 27/28 64bit
  • CoreOS 1298.6 64bit
  • Oracle Linux 6.9/7.3/7.4/7.5 64bit
  • Ubuntu 14.04/16.04/18.04/20.04 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 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 D1 ECS.
  • Both EVS disks and local disks can be used as data disks of a D1 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?
    

    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 long-term service data in local disks. Instead, back up data in a timely manner and use a high availability data architecture. Use EVS disks to store service data that needs to be stored for a long time.
• 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.
• The basic resources, including vCPUs, memory, and image of a stopped D2 ECS will continue to be billed. To stop the ECS from being billed, delete it and its associated resources. For details, see Will Am I Continue to Be Billed After ECSs Are Stopped?

Handling Damaged Local Disks Attached to an ECS of D Series

If a local disk attached to an ECS is damaged, perform the following operations to handle this issue:

For a Windows ECS:

1. Open Computer Management, choose Computer Management (Local) > Storage > Disk Management, and view the disk ID, for example, Disk 1.
2. Open Windows PowerShell as an administrator and obtain the serial number of the faulty disk according to the mapping between the disk ID and serial number.

   Get-Disk | select Number, SerialNumber

   Figure 3 Querying the mapping between the disk ID and serial number
   
3. Stop the ECS and provide the serial number of the faulty disk to technical support personnel to replace the local disk.

   After the local disk is replaced, restart the ECS to synchronize the new local disk information to the virtualization layer.