functions/Get-DbaMaxMemory.ps1

Function Get-DbaMaxMemory
{
<#
.SYNOPSIS
Gets the 'Max Server Memory' configuration setting and the memory of the server.
Works on SQL Server 2000-2014.

.DESCRIPTION
This cmdlet retrieves the SQL Server 'Max Server Memory' configuration setting as well as the total
physical installed on the server.

THIS CODE IS PROVIDED "AS IS", WITH NO WARRANTIES.

.PARAMETER SqlServer
Allows you to specify a comma separated list of servers to query.

.PARAMETER SqlCredential
Allows you to login to servers using SQL Logins as opposed to Windows Auth/Integrated/Trusted. To use:

$cred = Get-Credential, then pass $cred variable to this parameter.

Windows Authentication will be used when SqlCredential is not specified. To connect as a different Windows user, run PowerShell as that user.

.NOTES
Author : Chrissy LeMaire (@cl), netnerds.net
Requires: sysadmin access on SQL Servers

dbatools PowerShell module (https://dbatools.io, clemaire@gmail.com)
Copyright (C) 2016 Chrissy LeMaire

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

.LINK
https://dbatools.io/Get-DbaMaxMemory

.EXAMPLE
Get-DbaMaxMemory -SqlServer sqlcluster,sqlserver2012

Get memory settings for all servers within the SQL Server Central Management Server "sqlcluster".

.EXAMPLE
Get-DbaMaxMemory -SqlServer sqlcluster | Where-Object { $_.SqlMaxMB -gt $_.TotalMB }

Find all servers in Server Central Management Server that have 'Max Server Memory' set to higher than the total memory of the server (think 2147483647)

#>

    [CmdletBinding()]
    Param (
        [parameter(Position = 0, Mandatory = $true, ValueFromPipeline = $True)]
        [Alias("ServerInstance", "SqlInstance", "SqlServers")]
        [object]$SqlServer,
        [System.Management.Automation.PSCredential]$SqlCredential
    )
    
    PROCESS
    {
        $collection = @()
        foreach ($servername in $sqlserver)
        {    
            Write-Verbose "Attempting to connect to $servername"
            try
            {
                $server = Connect-SqlServer -SqlServer $servername -SqlCredential $SqlCredential
            }
            catch
            {
                Write-Warning "Can't connect to $servername or access denied. Skipping."
                continue
            }

            $totalmemory = $server.PhysicalMemory
            
            # Some servers under-report by 1MB.
            if (($totalmemory % 1024) -ne 0) { $totalmemory = $totalmemory + 1 }

            [pscustomobject]@{
                Server = $server.name
                TotalMB = $totalmemory
                SqlMaxMB = $server.Configuration.MaxServerMemory.ConfigValue
            }
        }
    }
}