Cim_PhysicalMemory 和 Win32_ComputerSystem 返回不同的内存量 [英] Cim_PhysicalMemory and Win32_ComputerSystem return different amount of memory

问题描述

我正在尝试编写一个 PowerShell 脚本，以显示服务器(具有 512 GB 的物理服务器)中安装的内存量.
我尝试了三种不同的方法，但得到了不同的结果.

I'm trying to write a PowerShell script that shows the amount of memory installed in a server (a physical server with 512 GB).
I've tried three different methods and I get different results.

1. Win32_PhysicalMemory

(Get-WmiObject Win32_PhysicalMemory | Measure-Object -Property Capacity -Sum).Sum)/1GB

这将返回 255.99 GB.

This returns 255.99 GB.

Win32_ComputerSystem

$InstalledRAM = Get-WmiObject -Class Win32_ComputerSystem
[Math]::Round(($InstalledRAM.TotalPhysicalMemory/1GB), 2)

这将返回 511.88 GB.

This returns 511.88 GB.

Cim_PhysicalMemory

$MaxRam = 0
$RamPool = (Get-CimInstance -Class "Cim_PhysicalMemory" | % {$_.Capacity})

foreach ($RamBank in $RamPool) {
    $MaxRam += $RamBank/1024/1024
}

这将返回 255.99 GB.

This returns 255.99 GB.

Taskmanager/systeminfo 显示安装了 512 GB.

Taskmanager/systeminfo show there is 512 GB installed.

当我使用 Win32_PhysicalMemory 打印出安装在不同内存条中的内存，我得到 8 个 32 GB 的内存条.但我确定服务器包含 512 GB.

When I use Win32_PhysicalMemory to print out the memory installed in the different memory banks, I get 8 banks of 32 GB. But I'm sure the server contains 512 GB.

有人可以向我解释为什么方法 1 和方法 3 只返回 256 GB 吗?

Can someone explain to me why method 1 and 3 only return 256 GB?

更新:
当我查看 bios 时，我看到为每个物理处理器分配了 256 GB.我的知识不是那么先进，但是否有可能我必须首先请求 NUMA 节点，然后 foreach 节点检索分配给它的内存量?或者 Powershell 无法做到这一点?

Update:
When I look in the bios I see that there is 256 GB assigned to each physical processor. My knowledge is not so advanced but is it possible that I have to request the NUMA-nodes first and foreach node retrieve the amount of memory assigned to it? Or is this not possible with Powershell?

推荐答案

CIM_PhysicalMemory 和 Win32_PhysicalMemory 是相同的 [1].

CIM_PhysicalMemory and Win32_PhysicalMemory are the same [1].

此属性继承自 CIM_PhysicalMemory.

This property is inherited from CIM_PhysicalMemory.

这是从[1].

该值来自 SMBIOS 版本信息中的 Memory Device 结构.对于 SMBIOS 2.1 到 2.6 版本，该值来自 Size 成员.对于 SMBIOS 2.7+ 版，该值来自扩展大小成员.

This value comes from the Memory Device structure in the SMBIOS version information. For SMBIOS versions 2.1 thru 2.6 the value comes from the Size member. For SMBIOS version 2.7+ the value comes from the Extended Size member.

SMBIOS 标准说 [2]

The SMBIOS standard says [2]

扩展大小字段旨在表示大于 32,767 MB (32 GB - 1 MB) 的内存设备，无法使用大小字段进行描述.此字段仅在 Size 字段中的值为 7FFFh 时才有意义.为了与旧的 SMBIOS 解析器兼容，小于 (32 GB - 1 MB) 的内存设备应该使用它们在 Size 字段中的大小来表示，而将 Extended Size 字段设置为 0.

The Extended Size field is intended to represent memory devices larger than 32,767 MB (32 GB - 1 MB), which cannot be described using the Size field. This field is only meaningful if the value in the Size field is 7FFFh. For compatibility with older SMBIOS parsers, memory devices smaller than (32 GB - 1 MB) should be represented using their size in the Size field, leaving the Extended Size field set to 0.

如您所说，您有 8x64GB，但显示为 8x32GB，这对我来说不像 NUMA 问题.如果是 NUMA，我希望你能显示 4x32GB.另外，我有一个带有 8x32GB 和 2 个套接字的服务器.因此，如果是 NUMA 问题，我希望在我的盒子上看到同样的问题.但是，我正确显示了金额.看起来您的 BIOS 使用 2.7.1 之前的 SMBIOS 标准结构，但这很奇怪，因为它是 2011 年的.

As you say, you have 8x64GB, but displayed 8x32GB, it doesn't like like a NUMA issue to me. If it's NUMA, I'd expect you get 4x32GB displayed. Also, I have a server with 8x32GB and 2 sockets. Hence, if it's a NUMA issue, I'd expect to see the same issue on my box. However, I get the amount displayed correctly. It looks like your BIOS uses SMBIOS standad strcuture before 2.7.1, which is strange though, as it's from 2011.

请尝试使用

(Get-CimInstance -ClassName Win32_BIOS) | Select-Object SMBIOS*

对我来说，SMBIOSVersion 返回供应商的 BIOS 版本号而不是标准，但 SMBIOSMajorVersion 和 SMBIOSMinorVersion 返回正确的值.

For me, SMBIOSVersion returns the vendor's BIOS version number instead of the standard, but SMBIOSMajorVersionand SMBIOSMinorVersion are returning the proper value.

Win32_ComputerSystem 从 Win32 api 查询信息 [3].

Win32_ComputerSystem queries the information from the Win32 api [3].

物理内存的总大小.请注意，在某些情况下，此属性可能不会返回物理内存的准确值.例如，如果 BIOS 正在使用某些物理内存，则它是不准确的.要获得准确的值，请改用 Win32_PhysicalMemory 中的容量属性.

Total size of physical memory. Be aware that, under some circumstances, this property may not return an accurate value for the physical memory. For example, it is not accurate if the BIOS is using some of the physical memory. For an accurate value, use the Capacity property in Win32_PhysicalMemory instead.

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