Large-Memory ECSs

Overview

Large-memory ECSs provide an even larger amount of memory than memory-optimized ECSs. They are used for applications that require a large amount of memory, rapid data switching, low latency, and process large volumes of data. Large-memory ECSs provide large memory and high computing, storage, and network performance.

• Applications

  Large-memory ECSs are suitable for applications that require a large amount of memory, rapid data switching, and low latency, and process large volumes of data.

• Application scenarios

  OLAP and OLTP applications with hyper-threading enabled

Specifications

Notes

• Large-memory ECSs do not support NIC hot swapping.
• Specifications of large-memory ECSs can be modified only within the same flavor family.
• Affected by the memory loading speed, large-memory ECSs may take longer to start.
• Table 2 lists the OSs supported by large-memory ECSs.

  Table 2 Supported OS versions

  OS	Version
  CentOS	CentOS 7.9 64bit CentOS 7.7 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
  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
  SUSE-SAP	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

• Large-memory ECSs can use ultra-high I/O EVS disks as the system disk and data disks.
• The primary and extension NICs of a large-memory ECS have specified application scenarios. For details, see Table 3.

  Table 3 Application scenarios of the NICs of a large-memory ECS

  NIC Type	Application Scenario	Remarks
  Primary NIC	Vertical layer 3 communication	N/A
  Extension NIC	Horizontal layer 2 communication	To improve network performance, you can set the MTU of an extension NIC to 8888.

• An ECS can have a maximum of 60 attached disks, including the system disk. For details about constraints, see Can I Attach Multiple Disks to an ECS?

  An example is provided as follows:

  An E3 ECS is to be created. It can have a maximum of 60 attached disks, where:

  • The number of system disks is 1.
  • The number of EVS disks is at most 59.
  

  The maximum number of disks attached to an existing large-memory ECS remains unchanged. To attach 60 disks, enable advanced disk. For details, see Enabling Advanced Disk.