Cannont Add-Member as the Member with the Name Exists - arrays

Question

Can someone help me out with getting the disk info? I have 3 disks but I'm unable to get their information using add member.
I get an error:
"Add-Member : Cannot add a member with the name "Disks" because a member with that name already exists. If you want to overwrite the member anyway, use the Force parameter to overwrite it."
This is my code:
function Get-Inven {
param([string[]]$computername)
#Import-Module ActiveDirectory
foreach ($computer in $computername) {
$disks = Get-WmiObject -Class Win32_LogicalDisk -ComputerName $computer -Filter 'DriveType=3'
$os = Get-WmiObject -Class Win32_OperatingSystem -ComputerName $computer
#$comp = Get-ADComputer -Filter { cn=$computer }
$info = #{
'ComputerName'=$computer;
'OSVersion'=$os.caption;
'DnsHostName'=$comp.dnshostname
}
$obj = New-Object -TypeName PSObject -Property $info
foreach ($disk in $disks) {
$info = #{
'DriveLetter'=$disk.deviceID;
'FreeSpace'=($disk.freespace / 1MB -as [int])
}
$diskobj = New-Object -TypeName PSObject -Property $Info
$obj | Add-Member -MemberType NoteProperty -Name Disks -Value $diskobj
}
}
}

Answer 1

You can still set the Name property if you add the -Force parameter. You should also add the -PassThru switch parameter to emit the object back to the pipeline:
$obj | Add-Member -MemberType NoteProperty -Name Disks -Value $diskobj -Force -PassThru
UPDATE:
In my opinion you can simplify the function (no add-member calls):
foreach ($computer in $computername) {
$disks = Get-WmiObject -Class Win32_LogicalDisk -ComputerName $computer -Filter 'DriveType=3'
$os = Get-WmiObject -Class Win32_OperatingSystem -ComputerName $computer
#$comp = Get-ADComputer -Filter { cn=$computer }
$info = #{
ComputerName=$computer
OSVersion=$os.caption
DnsHostName=$comp.dnshostname
FreeSpaceMB= ($disks | foreach { "{0},{1:N0}" -f $_.Caption,($_.freespace/1MB) }) -join ';'
}
New-Object -TypeName PSObject -Property $info
}

Answer 2

Since there are multiple disks, you need to create the disk property as an array, then add each disk to the array. Also, remember to output $obj at the end of the $computername foreach.
function Get-Inven {
param([string[]]$computername)
$computername = 'localhost'
foreach ($computer in $computername) {
$disks = Get-WmiObject -Class Win32_LogicalDisk -ComputerName $computer -Filter 'DriveType=3'
$os = Get-WmiObject -Class Win32_OperatingSystem -ComputerName $computer
#$comp = Get-ADComputer -Filter { cn=$computer }
$info = #{
'ComputerName'=$computer;
'OSVersion'=$os.caption;
'DnsHostName'=$comp.dnshostname
}
$obj = New-Object -TypeName PSObject -Property $info
$obj | Add-Member -MemberType NoteProperty -Name Disks -Value #()
$obj | Add-Member -MemberType ScriptProperty -Name DisksList -Value {
($this.Disks|%{$_.DriveLetter + ',' + $_.FreeSpace}) -join ';'
}
foreach ($disk in $disks) {
$info = #{
'DriveLetter'=$disk.deviceID;
'FreeSpace'=($disk.freespace / 1MB -as [int])
}
$diskobj = New-Object -TypeName PSObject -Property $Info
$obj.Disks += $diskobj
}
$obj
}
}
$result = get-inven localhost
$result| select "OSVersion","DnsHostName","ComputerName","DisksList"|ConvertTo-Csv